diff --git a/generator/dawn_json_generator.py b/generator/dawn_json_generator.py
index 87d76ba..72851b8 100644
--- a/generator/dawn_json_generator.py
+++ b/generator/dawn_json_generator.py
@@ -868,6 +868,14 @@
     return type_name.CamelCase() + method_name.CamelCase()
 
 
+def as_CppMethodSuffix(type_name, method_name):
+    assert not type_name.native and not method_name.native
+    original_method_name_str = method_name.CamelCase()
+    if method_name.chunks[-1] == 'f':
+        return type_name.CamelCase() + original_method_name_str[:-1]
+    return type_name.CamelCase() + original_method_name_str
+
+
 def as_frontendType(metadata, typ):
     if typ.category == 'object':
         return typ.name.CamelCase() + 'Base*'
@@ -914,6 +922,10 @@
     return any(arg.type.category == 'function pointer' for arg in method.arguments)
 
 
+def has_callback_info(method):
+    return method.return_type.name.get() == 'future' and any(
+        arg.name.get() == 'callback info' for arg in method.arguments)
+
 def make_base_render_params(metadata):
     c_prefix = metadata.c_prefix
 
@@ -954,6 +966,7 @@
             'as_cppEnum': as_cppEnum,
             'as_cMethod': as_cMethod,
             'as_MethodSuffix': as_MethodSuffix,
+            'as_CppMethodSuffix': as_CppMethodSuffix,
             'as_cProc': as_cProc,
             'as_cType': lambda name: as_cType(c_prefix, name),
             'as_cReturnType': lambda typ: as_cReturnType(c_prefix, typ),
@@ -1110,7 +1123,8 @@
         if 'mock_api' in targets:
             mock_params = [
                 RENDER_PARAMS_BASE, params_dawn, {
-                    'has_callback_arguments': has_callback_arguments
+                    'has_callback_arguments': has_callback_arguments,
+                    "has_callback_info": has_callback_info
                 }
             ]
             renders.append(
diff --git a/generator/templates/mock_api.cpp b/generator/templates/mock_api.cpp
index b66b27e..ec792af 100644
--- a/generator/templates/mock_api.cpp
+++ b/generator/templates/mock_api.cpp
@@ -41,7 +41,7 @@
                 {%- endfor -%}
             ) {
                 auto object = reinterpret_cast<ProcTableAsClass::Object*>(self);
-                return object->procs->{{as_MethodSuffix(type.name, method.name)}}(self
+                return object->procs->{{as_CppMethodSuffix(type.name, method.name)}}(self
                     {%- for arg in method.arguments -%}
                         , {{as_varName(arg.name)}}
                     {%- endfor -%}
@@ -74,43 +74,114 @@
     {% endfor %}
 }
 
+//* Generate the older Call*Callback if there is no Future call equivalent.
+//* Includes:
+//*   - setDeviceLostCallback
+//*   - setUncapturedErrorCallback
+//*   - setLoggingCallback
+{% set LegacyCallbackFunctions = ['set device lost callback', 'set uncaptured error callback', 'set logging callback'] %}
+
 {% for type in by_category["object"] %}
-    {% for method in type.methods if has_callback_arguments(method) %}
-        {% set Suffix = as_MethodSuffix(type.name, method.name) %}
-
-        {{as_cType(method.return_type.name)}} ProcTableAsClass::{{Suffix}}(
-            {{-as_cType(type.name)}} {{as_varName(type.name)}}
-            {%- for arg in method.arguments -%}
-                , {{as_annotated_cType(arg)}}
-            {%- endfor -%}
-        ) {
-            ProcTableAsClass::Object* object = reinterpret_cast<ProcTableAsClass::Object*>({{as_varName(type.name)}});
-            {% for callback_arg in method.arguments if callback_arg.type.category == 'function pointer' %}
-                object->m{{as_MethodSuffix(type.name, method.name)}}Callback = {{as_varName(callback_arg.name)}};
-            {% endfor %}
-            object->userdata = userdata;
-            return On{{as_MethodSuffix(type.name, method.name)}}(
-                {{-as_varName(type.name)}}
-                {%- for arg in method.arguments -%}
-                    , {{as_varName(arg.name)}}
-                {%- endfor -%}
-            );
-        }
-
-        {% for callback_arg in method.arguments if callback_arg.type.category == 'function pointer' %}
-            void ProcTableAsClass::Call{{Suffix}}Callback(
+    {% for method in type.methods %}
+        {% set Suffix = as_CppMethodSuffix(type.name, method.name) %}
+        {% if has_callback_arguments(method) %}
+            {{as_cType(method.return_type.name)}} ProcTableAsClass::{{Suffix}}(
                 {{-as_cType(type.name)}} {{as_varName(type.name)}}
-                {%- for arg in callback_arg.type.arguments -%}
-                    {%- if not loop.last -%}, {{as_annotated_cType(arg)}}{%- endif -%}
+                {%- for arg in method.arguments -%}
+                    , {{as_annotated_cType(arg)}}
                 {%- endfor -%}
             ) {
                 ProcTableAsClass::Object* object = reinterpret_cast<ProcTableAsClass::Object*>({{as_varName(type.name)}});
-                object->m{{Suffix}}Callback(
-                    {%- for arg in callback_arg.type.arguments -%}
-                        {%- if not loop.last -%}{{as_varName(arg.name)}}, {% endif -%}
-                    {%- endfor -%}
-                    object->userdata);
+                {% for arg in method.arguments if arg.type.category == 'function pointer' %}
+                    object->m{{Suffix + arg.name.CamelCase()}} = {{as_varName(arg.name)}};
+                    object->m{{Suffix}}Userdata = userdata;
+                {% endfor %}
+
+                {% if method.name.get() == 'pop error scope' %}
+                    //* Currently special casing popErrorScope since it has an old callback type.
+                    On{{Suffix}}({{-as_varName(type.name)}}, {.nextInChain = nullptr, .mode = WGPUCallbackMode_AllowProcessEvents, .callback = nullptr, .oldCallback = oldCallback, .userdata = userdata});
+                {% elif method.name.get() not in LegacyCallbackFunctions %}
+                    On{{Suffix}}(
+                        {{-as_varName(type.name)}}
+                        {%- for arg in method.arguments if arg.type.category != 'function pointer' and arg.type.name.get() != 'void *' -%}
+                            , {{as_varName(arg.name)}}
+                        {%- endfor -%}
+                        , {.nextInChain = nullptr, .mode = WGPUCallbackMode_AllowProcessEvents
+                        {%- for arg in method.arguments if arg.type.category == 'function pointer' -%}
+                            , .{{as_varName(arg.name)}} = {{as_varName(arg.name)}}
+                        {%- endfor -%}
+                        , .userdata = userdata});
+                {% else %}
+                    On{{Suffix}}(
+                        {{-as_varName(type.name)}}
+                        {%- for arg in method.arguments -%}
+                            , {{as_varName(arg.name)}}
+                        {%- endfor -%}
+                    );
+                {% endif %}
             }
+        {% elif has_callback_info(method) %}
+            {{as_cType(method.return_type.name)}} ProcTableAsClass::{{Suffix}}(
+                {{-as_cType(type.name)}} {{as_varName(type.name)}}
+                {%- for arg in method.arguments -%}
+                    , {{as_annotated_cType(arg)}}
+                {%- endfor -%}
+            ) {
+                ProcTableAsClass::Object* object = reinterpret_cast<ProcTableAsClass::Object*>({{as_varName(type.name)}});
+                {% for arg in method.arguments %}
+                    {% if arg.name.get() == 'callback info' %}
+                        {% for callback in types[arg.type.name.get()].members if callback.type.category == 'function pointer' %}
+                            object->m{{Suffix + callback.name.CamelCase()}} = {{as_varName(arg.name)}}.{{as_varName(callback.name)}};
+                            object->m{{Suffix}}Userdata = {{as_varName(arg.name)}}.userdata;
+                        {% endfor %}
+                    {% endif %}
+                {% endfor %}
+
+                On{{Suffix}}(
+                    {{-as_varName(type.name)}}
+                    {%- for arg in method.arguments -%}
+                        , {{as_varName(arg.name)}}
+                    {%- endfor -%}
+                );
+                return {mNextFutureID++};
+            }
+        {% endif %}
+    {% endfor %}
+
+    {% for method in type.methods if has_callback_info(method) or method.name.get() in LegacyCallbackFunctions %}
+        {% set Suffix = as_CppMethodSuffix(type.name, method.name) %}
+        {% for arg in method.arguments %}
+            {% if arg.name.get() == 'callback info' %}
+                {% for callback in types[arg.type.name.get()].members if callback.type.category == 'function pointer' %}
+                    void ProcTableAsClass::Call{{Suffix + callback.name.CamelCase()}}(
+                        {{-as_cType(type.name)}} {{as_varName(type.name)}}
+                        {%- for arg in callback.type.arguments -%}
+                            {%- if not loop.last -%}, {{as_annotated_cType(arg)}}{%- endif -%}
+                        {%- endfor -%}
+                    ) {
+                        ProcTableAsClass::Object* object = reinterpret_cast<ProcTableAsClass::Object*>({{as_varName(type.name)}});
+                        object->m{{Suffix + callback.name.CamelCase()}}(
+                            {%- for arg in callback.type.arguments -%}
+                                {%- if not loop.last -%}{{as_varName(arg.name)}}, {% endif -%}
+                            {%- endfor -%}
+                            object->m{{Suffix}}Userdata);
+                    }
+                {% endfor %}
+            {% elif arg.type.category == 'function pointer' %}
+                void ProcTableAsClass::Call{{Suffix + arg.name.CamelCase()}}(
+                    {{-as_cType(type.name)}} {{as_varName(type.name)}}
+                    {%- for arg in arg.type.arguments -%}
+                        {%- if not loop.last -%}, {{as_annotated_cType(arg)}}{%- endif -%}
+                    {%- endfor -%}
+                ) {
+                    ProcTableAsClass::Object* object = reinterpret_cast<ProcTableAsClass::Object*>({{as_varName(type.name)}});
+                    object->m{{Suffix + arg.name.CamelCase()}}(
+                        {%- for arg in arg.type.arguments -%}
+                            {%- if not loop.last -%}{{as_varName(arg.name)}}, {% endif -%}
+                        {%- endfor -%}
+                        object->m{{Suffix}}Userdata);
+                }
+            {% endif %}
         {% endfor %}
     {% endfor %}
 {% endfor %}
@@ -129,6 +200,6 @@
 
 void MockProcTable::IgnoreAllReleaseCalls() {
     {% for type in by_category["object"] %}
-        EXPECT_CALL(*this, {{as_MethodSuffix(type.name, Name("release"))}}(_)).Times(AnyNumber());
+        EXPECT_CALL(*this, {{as_CppMethodSuffix(type.name, Name("release"))}}(_)).Times(AnyNumber());
     {% endfor %}
 }
diff --git a/generator/templates/mock_api.h b/generator/templates/mock_api.h
index 0acfe8c..e30a33c 100644
--- a/generator/templates/mock_api.h
+++ b/generator/templates/mock_api.h
@@ -36,8 +36,11 @@
 #include "dawn/{{api}}.h"
 #include <gmock/gmock.h>
 
+#include <atomic>
 #include <memory>
 
+#include "dawn/common/FutureUtils.h"
+
 // An abstract base class representing a proc table so that API calls can be mocked. Most API calls
 // are directly represented by a delete virtual method but others need minimal state tracking to be
 // useful as mocks.
@@ -55,45 +58,66 @@
             {{as_cType(type.name)}} GetNew{{type.name.CamelCase()}}();
         {% endfor %}
 
-        {% for type in by_category["object"] %}
-            {% for method in type.methods if not has_callback_arguments(method) %}
-                virtual {{as_cType(method.return_type.name)}} {{as_MethodSuffix(type.name, method.name)}}(
-                    {{-as_cType(type.name)}} {{as_varName(type.name)}}
-                    {%- for arg in method.arguments -%}
-                        , {{as_annotated_cType(arg)}}
-                    {%- endfor -%}
-                ) = 0;
-            {% endfor %}
+        //* Generate the older Call*Callback if there is no Future call equivalent.
+        //* Includes:
+        //*   - setDeviceLostCallback
+        //*   - setUncapturedErrorCallback
+        //*   - setLoggingCallback
+        {%- set LegacyCallbackFunctions = ['set device lost callback', 'set uncaptured error callback', 'set logging callback'] %}
+
+        {%- for type in by_category["object"] %}
 
             virtual void {{as_MethodSuffix(type.name, Name("reference"))}}({{as_cType(type.name)}} self) = 0;
             virtual void {{as_MethodSuffix(type.name, Name("release"))}}({{as_cType(type.name)}} self) = 0;
+            {% for method in type.methods %}
+                {% set Suffix = as_CppMethodSuffix(type.name, method.name) %}
+                {% if not has_callback_arguments(method) and not has_callback_info(method) %}
+                    virtual {{as_cType(method.return_type.name)}} {{Suffix}}(
+                        {{-as_cType(type.name)}} {{as_varName(type.name)}}
+                        {%- for arg in method.arguments -%}
+                            , {{as_annotated_cType(arg)}}
+                        {%- endfor -%}
+                    ) = 0;
+                {% else %}
+                    //* For functions with callbacks, store callback and userdata and call the On* method.
+                    {{as_cType(method.return_type.name)}} {{Suffix}}(
+                        {{-as_cType(type.name)}} {{as_varName(type.name)}}
+                        {%- for arg in method.arguments -%}
+                            , {{as_annotated_cType(arg)}}
+                        {%- endfor -%}
+                    );
+                {% endif %}
+            {% endfor %}
 
-            {% for method in type.methods if has_callback_arguments(method) %}
-                {% set Suffix = as_MethodSuffix(type.name, method.name) %}
-                //* Stores callback and userdata and calls the On* method.
-                {{as_cType(method.return_type.name)}} {{Suffix}}(
-                    {{-as_cType(type.name)}} {{as_varName(type.name)}}
-                    {%- for arg in method.arguments -%}
-                        , {{as_annotated_cType(arg)}}
-                    {%- endfor -%}
-                );
+            {%- for method in type.methods if has_callback_info(method) or method.name.get() in LegacyCallbackFunctions %}
+
+                {% set Suffix = as_CppMethodSuffix(type.name, method.name) %}
                 //* The virtual function to call after saving the callback and userdata in the proc.
                 //* This function can be mocked.
-                virtual {{as_cType(method.return_type.name)}} On{{Suffix}}(
+                virtual void On{{Suffix}}(
                     {{-as_cType(type.name)}} {{as_varName(type.name)}}
                     {%- for arg in method.arguments -%}
                         , {{as_annotated_cType(arg)}}
                     {%- endfor -%}
                 ) = 0;
-
-                //* Calls the stored callback.
-                {% for callback_arg in method.arguments if callback_arg.type.category == 'function pointer' %}
-                    void Call{{as_MethodSuffix(type.name, method.name)}}Callback(
-                        {{-as_cType(type.name)}} {{as_varName(type.name)}}
-                        {%- for arg in callback_arg.type.arguments -%}
-                            {%- if not loop.last -%}, {{as_annotated_cType(arg)}}{%- endif -%}
-                        {%- endfor -%}
-                    );
+                {% for arg in method.arguments %}
+                    {% if arg.name.get() == 'callback info' %}
+                        {% for callback in types[arg.type.name.get()].members if callback.type.category == 'function pointer' %}
+                            void Call{{Suffix + callback.name.CamelCase()}}(
+                                {{-as_cType(type.name)}} {{as_varName(type.name)}}
+                                {%- for arg in callback.type.arguments -%}
+                                    {%- if not loop.last -%}, {{as_annotated_cType(arg)}}{%- endif -%}
+                                {%- endfor -%}
+                            );
+                        {% endfor %}
+                    {% elif arg.type.category == 'function pointer' %}
+                        void Call{{Suffix + arg.name.CamelCase()}}(
+                            {{-as_cType(type.name)}} {{as_varName(type.name)}}
+                            {%- for arg in arg.type.arguments -%}
+                                {%- if not loop.last -%}, {{as_annotated_cType(arg)}}{%- endif -%}
+                            {%- endfor -%}
+                        );
+                    {% endif %}
                 {% endfor %}
             {% endfor %}
         {% endfor %}
@@ -101,18 +125,26 @@
         struct Object {
             ProcTableAsClass* procs = nullptr;
             {% for type in by_category["object"] %}
-                {% for method in type.methods if has_callback_arguments(method) %}
-                    {% for callback_arg in method.arguments if callback_arg.type.category == 'function pointer' %}
-                        {{as_cType(callback_arg.type.name)}} m{{as_MethodSuffix(type.name, method.name)}}Callback = nullptr;
+                {% for method in type.methods if has_callback_info(method) or method.name.get() in LegacyCallbackFunctions %}
+                    void* m{{as_CppMethodSuffix(type.name, method.name)}}Userdata = 0;
+                    {% for arg in method.arguments %}
+                        {% if arg.name.get() == 'callback info' %}
+                            {% for callback in types[arg.type.name.get()].members if callback.type.category == 'function pointer' %}
+                                {{as_cType(callback.type.name)}} m{{as_CppMethodSuffix(type.name, method.name)}}{{callback.name.CamelCase()}} = nullptr;
+                            {% endfor %}
+                        {% elif arg.type.category == 'function pointer' %}
+                            {{as_cType(arg.type.name)}} m{{as_CppMethodSuffix(type.name, method.name)}}{{arg.name.CamelCase()}} = nullptr;
+                        {% endif %}
                     {% endfor %}
                 {% endfor %}
             {% endfor %}
-            void* userdata = 0;
         };
 
     private:
         // Remembers the values returned by GetNew* so they can be freed.
         std::vector<std::unique_ptr<Object>> mObjects;
+        // Increasing futureID for testing purposes.
+        std::atomic<dawn::FutureID> mNextFutureID = 1;
 };
 
 class MockProcTable : public ProcTableAsClass {
@@ -122,8 +154,11 @@
 
         void IgnoreAllReleaseCalls();
 
-        {% for type in by_category["object"] %}
-            {% for method in type.methods if not has_callback_arguments(method) %}
+        {%- for type in by_category["object"] %}
+
+            MOCK_METHOD(void, {{as_MethodSuffix(type.name, Name("reference"))}}, ({{as_cType(type.name)}} self), (override));
+            MOCK_METHOD(void, {{as_MethodSuffix(type.name, Name("release"))}}, ({{as_cType(type.name)}} self), (override));
+            {% for method in type.methods if not has_callback_arguments(method) and not has_callback_info(method) %}
                 MOCK_METHOD({{as_cType(method.return_type.name)}},{{" "}}
                     {{-as_MethodSuffix(type.name, method.name)}}, (
                         {{-as_cType(type.name)}} {{as_varName(type.name)}}
@@ -133,12 +168,9 @@
                     ), (override));
             {% endfor %}
 
-            MOCK_METHOD(void, {{as_MethodSuffix(type.name, Name("reference"))}}, ({{as_cType(type.name)}} self), (override));
-            MOCK_METHOD(void, {{as_MethodSuffix(type.name, Name("release"))}}, ({{as_cType(type.name)}} self), (override));
-
-            {% for method in type.methods if has_callback_arguments(method) %}
-                MOCK_METHOD({{as_cType(method.return_type.name)}},{{" "-}}
-                    On{{as_MethodSuffix(type.name, method.name)}}, (
+            {% for method in type.methods if has_callback_info(method) or method.name.get() in LegacyCallbackFunctions %}
+                MOCK_METHOD(void,{{" "-}}
+                    On{{as_CppMethodSuffix(type.name, method.name)}}, (
                         {{-as_cType(type.name)}} {{as_varName(type.name)}}
                         {%- for arg in method.arguments -%}
                             , {{as_annotated_cType(arg)}}
diff --git a/src/dawn/dawn.json b/src/dawn/dawn.json
index aba2cd4..5864f39 100644
--- a/src/dawn/dawn.json
+++ b/src/dawn/dawn.json
@@ -1444,7 +1444,7 @@
             {
                 "name": "pop error scope",
                 "args": [
-                    {"name": "callback", "type": "error callback"},
+                    {"name": "old callback", "type": "error callback"},
                     {"name": "userdata", "type": "void *"}
                 ]
             },
diff --git a/src/dawn/tests/unittests/wire/WireAdapterTests.cpp b/src/dawn/tests/unittests/wire/WireAdapterTests.cpp
index 20ce02c..5588561 100644
--- a/src/dawn/tests/unittests/wire/WireAdapterTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireAdapterTests.cpp
@@ -72,7 +72,7 @@
     wgpu::DeviceDescriptor desc = {};
     AdapterRequestDevice(adapter, &desc);
 
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce(WithArg<1>(Invoke([&](const WGPUDeviceDescriptor* apiDesc) {
             EXPECT_EQ(apiDesc->label, nullptr);
             EXPECT_EQ(apiDesc->requiredFeatureCount, 0u);
@@ -95,7 +95,7 @@
 TEST_P(WireAdapterTests, RequestDeviceNullDescriptor) {
     AdapterRequestDevice(adapter, nullptr);
 
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce(WithArg<1>(Invoke([&](const WGPUDeviceDescriptor* apiDesc) {
             EXPECT_EQ(apiDesc->label, nullptr);
             EXPECT_EQ(apiDesc->requiredFeatureCount, 0u);
@@ -126,7 +126,7 @@
 
     AdapterRequestDevice(adapter, &desc);
 
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce(WithArg<1>(Invoke([&](const WGPUDeviceDescriptor* apiDesc) {
             EXPECT_STREQ(apiDesc->label, desc.label);
 
@@ -166,7 +166,7 @@
     // The backend device should not be known by the wire server.
     EXPECT_FALSE(GetWireServer()->IsDeviceKnown(apiDevice));
 
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             // Set on device creation to forward callbacks to the client.
             EXPECT_CALL(api, OnDeviceSetUncapturedErrorCallback(apiDevice, NotNull(), NotNull()))
@@ -270,7 +270,7 @@
     // The reply contains features that the device implementation supports, but the
     // wire does not.
     WGPUDevice apiDevice = api.GetNewDevice();
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             EXPECT_CALL(api, DeviceEnumerateFeatures(apiDevice, nullptr))
                 .WillOnce(Return(fakeFeatures.size()));
@@ -308,7 +308,7 @@
     AdapterRequestDevice(adapter, &desc, this);
 
     // Expect the server to receive the message. Then, mock an error.
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallAdapterRequestDeviceCallback(apiAdapter, WGPURequestDeviceStatus_Error, nullptr,
                                                  "Request device failed");
@@ -343,7 +343,7 @@
 
     // Mock a reply from the server.
     WGPUDevice apiDevice = api.GetNewDevice();
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             // Set on device creation to forward callbacks to the client.
             EXPECT_CALL(api, OnDeviceSetUncapturedErrorCallback(apiDevice, NotNull(), NotNull()))
diff --git a/src/dawn/tests/unittests/wire/WireBufferMappingTests.cpp b/src/dawn/tests/unittests/wire/WireBufferMappingTests.cpp
index d72f166..a6d14b4 100644
--- a/src/dawn/tests/unittests/wire/WireBufferMappingTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireBufferMappingTests.cpp
@@ -134,7 +134,7 @@
         BufferMapAsync(buffer, mapMode, 0, kBufferSize, nullptr);
 
         uint32_t bufferContent = 31337;
-        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
             .WillOnce(InvokeWithoutArgs([&] {
                 api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success);
             }));
@@ -173,7 +173,7 @@
         SetupBuffer(mapMode);
         BufferMapAsync(buffer, mapMode, 0, kBufferSize, nullptr);
 
-        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
             .WillOnce(InvokeWithoutArgs([&] {
                 api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
             }));
@@ -216,7 +216,7 @@
         BufferMapAsync(buffer, mapMode, 0, kBufferSize, nullptr);
 
         uint32_t bufferContent = 31337;
-        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
             .WillOnce(InvokeWithoutArgs([&] {
                 api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success);
             }));
@@ -256,7 +256,7 @@
     SetupBuffer(mapMode);
     BufferMapAsync(buffer, mapMode, 0, kBufferSize, nullptr);
 
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
         }));
@@ -339,7 +339,7 @@
     BufferMapAsync(buffer, WGPUMapMode_Read, 0, kBufferSize, nullptr);
 
     uint32_t bufferContent = 31337;
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(api, BufferGetConstMappedRange(apiBuffer, 0, kBufferSize))
@@ -367,7 +367,7 @@
     BufferMapAsync(buffer, WGPUMapMode_Read, 0, kBufferSize, nullptr);
 
     uint32_t bufferContent = 31337;
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(api, BufferGetConstMappedRange(apiBuffer, 0, kBufferSize))
@@ -384,7 +384,7 @@
     // Map failure while the buffer is already mapped
     BufferMapAsync(buffer, WGPUMapMode_Read, 0, kBufferSize, nullptr);
 
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
         }));
@@ -419,7 +419,7 @@
     uint32_t serverBufferContent = 31337;
     uint32_t updatedContent = 4242;
 
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(api, BufferGetMappedRange(apiBuffer, 0, kBufferSize))
@@ -456,7 +456,7 @@
     BufferMapAsync(buffer, WGPUMapMode_Write, 0, kBufferSize, nullptr);
 
     uint32_t bufferContent = 31337;
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(api, BufferGetMappedRange(apiBuffer, 0, kBufferSize))
@@ -472,7 +472,7 @@
 
     // Map failure while the buffer is already mapped
     BufferMapAsync(buffer, WGPUMapMode_Write, 0, kBufferSize, nullptr);
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
         }));
@@ -562,7 +562,7 @@
 
     BufferMapAsync(buffer, WGPUMapMode_Write, 0, kBufferSize, nullptr);
 
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(api, BufferGetMappedRange(apiBuffer, 0, kBufferSize))
@@ -597,7 +597,7 @@
 
     // Note that the validation logic is entirely on the native side so we inject the validation
     // error here and flush the server response to mock the expected behavior.
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
         }));
@@ -666,7 +666,7 @@
     BufferMapAsync(buffer, mapMode, 0, kBufferSize, nullptr);
 
     uint32_t bufferContent = 0;
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     ExpectMappedRangeCall(kBufferSize, &bufferContent);
@@ -702,7 +702,7 @@
 
     // Calls for the first successful map.
     uint32_t bufferContent = 0;
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     ExpectMappedRangeCall(kBufferSize, &bufferContent);
@@ -745,7 +745,7 @@
     uint32_t bufferContent = 31337;
     // Server-side success case
     {
-        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
             .WillOnce(InvokeWithoutArgs([&] {
                 api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success);
             }));
@@ -783,7 +783,7 @@
 
     // Server-side error case
     {
-        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+        EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
             .WillOnce(InvokeWithoutArgs([&] {
                 api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
             }));
@@ -822,7 +822,7 @@
     BufferMapAsync(buffer, mapMode, 0, kBufferSize, nullptr);
 
     uint32_t bufferContent = 0;
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     ExpectMappedRangeCall(kBufferSize, &bufferContent);
@@ -851,7 +851,7 @@
     BufferMapAsync(buffer, mapMode, 0, kBufferSize, nullptr);
 
     uint32_t bufferContent = 0;
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, mapMode, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     ExpectMappedRangeCall(kBufferSize, &bufferContent);
diff --git a/src/dawn/tests/unittests/wire/WireCreatePipelineAsyncTests.cpp b/src/dawn/tests/unittests/wire/WireCreatePipelineAsyncTests.cpp
index b712e6f..ff17f30 100644
--- a/src/dawn/tests/unittests/wire/WireCreatePipelineAsyncTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireCreatePipelineAsyncTests.cpp
@@ -119,7 +119,7 @@
 TEST_P(WireCreateComputePipelineAsyncTest, CreateSuccess) {
     DeviceCreateComputePipelineAsync(device, &mDescriptor, this);
 
-    EXPECT_CALL(api, OnDeviceCreateComputePipelineAsync(apiDevice, _, _, _))
+    EXPECT_CALL(api, OnDeviceCreateComputePipelineAsync(apiDevice, _, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallDeviceCreateComputePipelineAsyncCallback(
                 apiDevice, WGPUCreatePipelineAsyncStatus_Success, nullptr, "");
@@ -139,7 +139,7 @@
 TEST_P(WireCreateComputePipelineAsyncTest, CreateError) {
     DeviceCreateComputePipelineAsync(device, &mDescriptor, this);
 
-    EXPECT_CALL(api, OnDeviceCreateComputePipelineAsync(apiDevice, _, _, _))
+    EXPECT_CALL(api, OnDeviceCreateComputePipelineAsync(apiDevice, _, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallDeviceCreateComputePipelineAsyncCallback(
                 apiDevice, WGPUCreatePipelineAsyncStatus_ValidationError, nullptr,
@@ -161,7 +161,7 @@
 TEST_P(WireCreateRenderPipelineAsyncTest, CreateSuccess) {
     DeviceCreateRenderPipelineAsync(device, &mDescriptor, this);
 
-    EXPECT_CALL(api, OnDeviceCreateRenderPipelineAsync(apiDevice, _, _, _))
+    EXPECT_CALL(api, OnDeviceCreateRenderPipelineAsync(apiDevice, _, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallDeviceCreateRenderPipelineAsyncCallback(
                 apiDevice, WGPUCreatePipelineAsyncStatus_Success, nullptr, "");
@@ -181,7 +181,7 @@
 TEST_P(WireCreateRenderPipelineAsyncTest, CreateError) {
     DeviceCreateRenderPipelineAsync(device, &mDescriptor, this);
 
-    EXPECT_CALL(api, OnDeviceCreateRenderPipelineAsync(apiDevice, _, _, _))
+    EXPECT_CALL(api, OnDeviceCreateRenderPipelineAsync(apiDevice, _, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallDeviceCreateRenderPipelineAsyncCallback(
                 apiDevice, WGPUCreatePipelineAsyncStatus_ValidationError, nullptr,
@@ -204,7 +204,7 @@
 TEST_P(WireCreateRenderPipelineAsyncTest, CreateThenDisconnect) {
     DeviceCreateRenderPipelineAsync(device, &mDescriptor, this);
 
-    EXPECT_CALL(api, OnDeviceCreateRenderPipelineAsync(apiDevice, _, _, _))
+    EXPECT_CALL(api, OnDeviceCreateRenderPipelineAsync(apiDevice, _, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallDeviceCreateRenderPipelineAsyncCallback(
                 apiDevice, WGPUCreatePipelineAsyncStatus_Success, nullptr, "");
@@ -225,7 +225,7 @@
 TEST_P(WireCreateComputePipelineAsyncTest, CreateThenDisconnect) {
     DeviceCreateComputePipelineAsync(device, &mDescriptor, this);
 
-    EXPECT_CALL(api, OnDeviceCreateComputePipelineAsync(apiDevice, _, _, _))
+    EXPECT_CALL(api, OnDeviceCreateComputePipelineAsync(apiDevice, _, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallDeviceCreateComputePipelineAsyncCallback(
                 apiDevice, WGPUCreatePipelineAsyncStatus_Success, nullptr, "");
diff --git a/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp b/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp
index 31ad03c..0ee6996 100644
--- a/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp
@@ -201,7 +201,7 @@
     // Overridden version of wgpuDevicePopErrorScope that defers to the API call based on the test
     // callback mode.
     void DevicePopErrorScope(WGPUDevice d, void* userdata = nullptr) {
-        if (this->IsAsync()) {
+        if (IsAsync()) {
             wgpuDevicePopErrorScope(d, mMockOldCb.Callback(), mMockOldCb.MakeUserdata(userdata));
         } else {
             WGPUPopErrorScopeCallbackInfo callbackInfo = {};
@@ -212,6 +212,17 @@
         }
     }
 
+    // Overridden version of api.CallDevicePopErrorScopeCallback to defer to the correct callback
+    // depending on the test callback mode. Note that currently, the ServerDevice calls the native
+    // procs using the old-non-future signature. Once that changes, we can probably just inline
+    // api.CallDevicePopErrorScopeCallback calls in place of this function.
+    void CallDevicePopErrorScopeCallback(WGPUDevice d,
+                                         WGPUPopErrorScopeStatus status,
+                                         WGPUErrorType type,
+                                         char const* message) {
+        api.CallDevicePopErrorScopeOldCallback(d, type, message);
+    }
+
     void PushErrorScope(WGPUErrorFilter filter) {
         EXPECT_CALL(api, DevicePushErrorScope(apiDevice, filter)).Times(1);
         wgpuDevicePushErrorScope(device, filter);
@@ -247,9 +258,10 @@
         PushErrorScope(filter);
 
         DevicePopErrorScope(device, this);
-        EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _, _)).WillOnce(InvokeWithoutArgs([&] {
-            api.CallDevicePopErrorScopeCallback(apiDevice, type, "Some error message");
-        }));
+        EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _)).WillOnce([&] {
+            CallDevicePopErrorScopeCallback(apiDevice, WGPUPopErrorScopeStatus_Success, type,
+                                            "Some error message");
+        });
 
         FlushClient();
         FlushFutures();
@@ -275,7 +287,7 @@
     PushErrorScope(WGPUErrorFilter_Validation);
 
     DevicePopErrorScope(device, this);
-    EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _, _)).Times(1);
+    EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _)).Times(1);
 
     FlushClient();
     FlushFutures();
@@ -303,9 +315,9 @@
     PushErrorScope(WGPUErrorFilter_Validation);
 
     DevicePopErrorScope(device, this);
-    EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _, _)).WillOnce(InvokeWithoutArgs([&] {
-        api.CallDevicePopErrorScopeCallback(apiDevice, WGPUErrorType_Validation,
-                                            "Some error message");
+    EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _)).WillOnce(InvokeWithoutArgs([&] {
+        CallDevicePopErrorScopeCallback(apiDevice, WGPUPopErrorScopeStatus_Success,
+                                        WGPUErrorType_Validation, "Some error message");
     }));
 
     FlushClient();
@@ -328,9 +340,9 @@
 // Empty stack (We are emulating the errors that would be callback-ed from native).
 TEST_P(WirePopErrorScopeCallbackTests, EmptyStack) {
     DevicePopErrorScope(device, this);
-    EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _, _)).WillOnce(InvokeWithoutArgs([&] {
-        api.CallDevicePopErrorScopeCallback(apiDevice, WGPUErrorType_Validation,
-                                            "No error scopes to pop");
+    EXPECT_CALL(api, OnDevicePopErrorScope(apiDevice, _)).WillOnce(InvokeWithoutArgs([&] {
+        CallDevicePopErrorScopeCallback(apiDevice, WGPUPopErrorScopeStatus_Success,
+                                        WGPUErrorType_Validation, "No error scopes to pop");
     }));
 
     FlushClient();
diff --git a/src/dawn/tests/unittests/wire/WireInstanceTests.cpp b/src/dawn/tests/unittests/wire/WireInstanceTests.cpp
index 9ea7334..bdf6e34 100644
--- a/src/dawn/tests/unittests/wire/WireInstanceTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireInstanceTests.cpp
@@ -94,7 +94,7 @@
 
         InstanceRequestAdapter(instance, &options, nullptr);
 
-        EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), NotNull(), NotNull()))
+        EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), _))
             .WillOnce(WithArg<1>(Invoke([&](const WGPURequestAdapterOptions* apiOptions) {
                 EXPECT_EQ(apiOptions->powerPreference,
                           static_cast<WGPUPowerPreference>(options.powerPreference));
@@ -140,7 +140,7 @@
 
     // Expect the server to receive the message. Then, mock a fake reply.
     WGPUAdapter apiAdapter = api.GetNewAdapter();
-    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             EXPECT_CALL(api, AdapterHasFeature(apiAdapter, _)).WillRepeatedly(Return(false));
 
@@ -233,7 +233,7 @@
 
     // Expect the server to receive the message. Then, mock a fake reply.
     WGPUAdapter apiAdapter = api.GetNewAdapter();
-    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             for (WGPUFeatureName feature : fakeFeatures) {
                 EXPECT_CALL(api, AdapterHasFeature(apiAdapter, feature)).WillOnce(Return(true));
@@ -344,7 +344,7 @@
 
     // Expect the server to receive the message. Then, mock a fake reply.
     WGPUAdapter apiAdapter = api.GetNewAdapter();
-    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             EXPECT_CALL(api, AdapterHasFeature(apiAdapter, _)).WillRepeatedly(Return(false));
 
@@ -400,7 +400,7 @@
     InstanceRequestAdapter(instance, &options, nullptr);
 
     // Expect the server to receive the message. Then, mock an error.
-    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallInstanceRequestAdapterCallback(apiInstance, WGPURequestAdapterStatus_Error,
                                                    nullptr, "Some error");
diff --git a/src/dawn/tests/unittests/wire/WireMemoryTransferServiceTests.cpp b/src/dawn/tests/unittests/wire/WireMemoryTransferServiceTests.cpp
index 79ea2b8..d50cc92 100644
--- a/src/dawn/tests/unittests/wire/WireMemoryTransferServiceTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireMemoryTransferServiceTests.cpp
@@ -363,7 +363,7 @@
     ExpectServerReadHandleSerializeDataUpdate(serverHandle);
 
     // Mock a successful callback
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(clientMemoryTransferService, OnReadHandleGetData(clientHandle))
@@ -435,7 +435,7 @@
     wgpuBufferMapAsync(buffer, WGPUMapMode_Read, 0, kBufferSize, ToMockBufferMapCallback, nullptr);
 
     // Mock a failed callback.
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
         }));
@@ -512,7 +512,7 @@
     ExpectServerReadHandleSerializeDataUpdate(serverHandle);
 
     // Mock a successful callback
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(api, BufferGetConstMappedRange(apiBuffer, 0, kBufferSize))
@@ -557,7 +557,7 @@
     ExpectServerReadHandleSerializeDataUpdate(serverHandle);
 
     // Mock a successful callback
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Read, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(clientMemoryTransferService, OnReadHandleGetData(clientHandle))
@@ -611,7 +611,7 @@
     wgpuBufferMapAsync(buffer, WGPUMapMode_Write, 0, kBufferSize, ToMockBufferMapCallback, nullptr);
 
     // Mock a successful callback.
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(clientMemoryTransferService, OnWriteHandleGetData(clientHandle))
@@ -690,7 +690,7 @@
     wgpuBufferMapAsync(buffer, WGPUMapMode_Write, 0, kBufferSize, ToMockBufferMapCallback, nullptr);
 
     // Mock an error callback.
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_ValidationError);
         }));
@@ -764,7 +764,7 @@
     wgpuBufferMapAsync(buffer, WGPUMapMode_Write, 0, kBufferSize, ToMockBufferMapCallback, nullptr);
 
     // Mock a successful callback.
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(clientMemoryTransferService, OnWriteHandleGetData(clientHandle))
@@ -815,7 +815,7 @@
     wgpuBufferMapAsync(buffer, WGPUMapMode_Write, 0, kBufferSize, ToMockBufferMapCallback, nullptr);
 
     // Mock a successful callback.
-    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _, _))
+    EXPECT_CALL(api, OnBufferMapAsync(apiBuffer, WGPUMapMode_Write, 0, kBufferSize, _))
         .WillOnce(InvokeWithoutArgs(
             [&] { api.CallBufferMapAsyncCallback(apiBuffer, WGPUBufferMapAsyncStatus_Success); }));
     EXPECT_CALL(clientMemoryTransferService, OnWriteHandleGetData(clientHandle))
diff --git a/src/dawn/tests/unittests/wire/WireQueueTests.cpp b/src/dawn/tests/unittests/wire/WireQueueTests.cpp
index b79f268..45d375e 100644
--- a/src/dawn/tests/unittests/wire/WireQueueTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireQueueTests.cpp
@@ -54,7 +54,7 @@
 // Test that a successful OnSubmittedWorkDone call is forwarded to the client.
 TEST_P(WireQueueTests, OnSubmittedWorkDoneSuccess) {
     QueueOnSubmittedWorkDone(queue);
-    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _, _)).WillOnce(InvokeWithoutArgs([&] {
+    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _)).WillOnce(InvokeWithoutArgs([&] {
         api.CallQueueOnSubmittedWorkDoneCallback(apiQueue, WGPUQueueWorkDoneStatus_Success);
     }));
     FlushClient();
@@ -70,7 +70,7 @@
 // Test that an error OnSubmittedWorkDone call is forwarded as an error to the client.
 TEST_P(WireQueueTests, OnSubmittedWorkDoneError) {
     QueueOnSubmittedWorkDone(queue);
-    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _, _)).WillOnce(InvokeWithoutArgs([&] {
+    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _)).WillOnce(InvokeWithoutArgs([&] {
         api.CallQueueOnSubmittedWorkDoneCallback(apiQueue, WGPUQueueWorkDoneStatus_Error);
     }));
     FlushClient();
@@ -91,7 +91,7 @@
     DAWN_SKIP_TEST_IF(IsSpontaneous());
 
     QueueOnSubmittedWorkDone(queue);
-    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _, _)).WillOnce(InvokeWithoutArgs([&] {
+    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _)).WillOnce(InvokeWithoutArgs([&] {
         api.CallQueueOnSubmittedWorkDoneCallback(apiQueue, WGPUQueueWorkDoneStatus_Error);
     }));
     FlushClient();
@@ -109,7 +109,7 @@
 // dropped.
 TEST_P(WireQueueTests, OnSubmittedWorkDoneBeforeDisconnectBeforeReply) {
     QueueOnSubmittedWorkDone(queue);
-    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _, _)).WillOnce(InvokeWithoutArgs([&] {
+    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _)).WillOnce(InvokeWithoutArgs([&] {
         api.CallQueueOnSubmittedWorkDoneCallback(apiQueue, WGPUQueueWorkDoneStatus_Error);
     }));
     FlushClient();
@@ -137,7 +137,7 @@
 TEST_P(WireQueueTests, OnSubmittedWorkDoneInsideCallbackBeforeDisconnect) {
     static constexpr size_t kNumRequests = 10;
     QueueOnSubmittedWorkDone(queue);
-    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _, _)).WillOnce(InvokeWithoutArgs([&] {
+    EXPECT_CALL(api, OnQueueOnSubmittedWorkDone(apiQueue, _)).WillOnce(InvokeWithoutArgs([&] {
         api.CallQueueOnSubmittedWorkDoneCallback(apiQueue, WGPUQueueWorkDoneStatus_Error);
     }));
     FlushClient();
diff --git a/src/dawn/tests/unittests/wire/WireShaderModuleTests.cpp b/src/dawn/tests/unittests/wire/WireShaderModuleTests.cpp
index 495a9eb..91cc44b 100644
--- a/src/dawn/tests/unittests/wire/WireShaderModuleTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireShaderModuleTests.cpp
@@ -77,7 +77,7 @@
 TEST_P(WireShaderModuleTests, GetCompilationInfo) {
     ShaderModuleGetCompilationInfo(shaderModule);
 
-    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _, _))
+    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallShaderModuleGetCompilationInfoCallback(
                 apiShaderModule, WGPUCompilationInfoRequestStatus_Success, &mCompilationInfo);
@@ -112,7 +112,7 @@
 TEST_P(WireShaderModuleTests, GetCompilationInfoBeforeDisconnect) {
     ShaderModuleGetCompilationInfo(shaderModule);
 
-    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _, _))
+    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallShaderModuleGetCompilationInfoCallback(
                 apiShaderModule, WGPUCompilationInfoRequestStatus_Success, &mCompilationInfo);
@@ -149,7 +149,7 @@
 
     ShaderModuleGetCompilationInfo(shaderModule);
 
-    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _, _))
+    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallShaderModuleGetCompilationInfoCallback(
                 apiShaderModule, WGPUCompilationInfoRequestStatus_Success, &mCompilationInfo);
@@ -178,7 +178,7 @@
 
     ShaderModuleGetCompilationInfo(shaderModule);
 
-    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _, _))
+    EXPECT_CALL(api, OnShaderModuleGetCompilationInfo(apiShaderModule, _))
         .WillOnce(InvokeWithoutArgs([&] {
             api.CallShaderModuleGetCompilationInfoCallback(
                 apiShaderModule, WGPUCompilationInfoRequestStatus_Success, &mCompilationInfo);
diff --git a/src/dawn/tests/unittests/wire/WireTest.cpp b/src/dawn/tests/unittests/wire/WireTest.cpp
index 9ce777b..67ce338 100644
--- a/src/dawn/tests/unittests/wire/WireTest.cpp
+++ b/src/dawn/tests/unittests/wire/WireTest.cpp
@@ -93,7 +93,7 @@
     MockCallback<WGPURequestAdapterCallback> adapterCb;
     wgpuInstanceRequestAdapter(instance, &adapterOpts, adapterCb.Callback(),
                                adapterCb.MakeUserdata(this));
-    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnInstanceRequestAdapter(apiInstance, NotNull(), _))
         .WillOnce([&]() {
             EXPECT_CALL(api, AdapterHasFeature(apiAdapter, _)).WillRepeatedly(Return(false));
 
@@ -133,7 +133,7 @@
     MockCallback<WGPURequestDeviceCallback> deviceCb;
     wgpuAdapterRequestDevice(adapter.Get(), &deviceDesc, deviceCb.Callback(),
                              deviceCb.MakeUserdata(this));
-    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), NotNull(), NotNull()))
+    EXPECT_CALL(api, OnAdapterRequestDevice(apiAdapter, NotNull(), _))
         .WillOnce([&]() {
             // Set on device creation to forward callbacks to the client.
             EXPECT_CALL(api, OnDeviceSetUncapturedErrorCallback(apiDevice, NotNull(), NotNull()))