diff --git a/src/dawn_wire/client/Buffer.cpp b/src/dawn_wire/client/Buffer.cpp
index b735280..2233c81 100644
--- a/src/dawn_wire/client/Buffer.cpp
+++ b/src/dawn_wire/client/Buffer.cpp
@@ -303,9 +303,6 @@
         //   - Unmap locally on the client
         //   - Server -> Client: Result of MapRequest2
 
-        // TODO(dawn:608): mDevice->InjectError(WGPUErrorType_Validation) for map oom failure
-        // and separate from buffer destroyed before unmap case
-
         // mWriteHandle can still be nullptr if buffer has been destroyed before unmap
         if ((mMapState == MapState::MappedForWrite || mMapState == MapState::MappedAtCreation) &&
             mWriteHandle != nullptr) {
@@ -364,8 +361,6 @@
         BufferUnmapCmd cmd;
         cmd.self = ToAPI(this);
         client->SerializeCommand(cmd);
-        // TODO(dawn:608): add tracking mapped status and change to return bool for returning unmap
-        // success/failure
     }
 
     void Buffer::Destroy() {
diff --git a/src/include/dawn_wire/WireClient.h b/src/include/dawn_wire/WireClient.h
index 961e045..bbcaaee 100644
--- a/src/include/dawn_wire/WireClient.h
+++ b/src/include/dawn_wire/WireClient.h
@@ -112,31 +112,17 @@
                 // Simply return the base address of the allocation (without applying any offset)
                 // Returns nullptr if the allocation failed.
                 // The data must live at least until the ReadHandle is destructued
-                // TODO(dawn:773): change to pure virtual after update on chromium side.
-                virtual const void* GetData() {
-                    return nullptr;
-                }
+                virtual const void* GetData() = 0;
 
                 // Gets called when a MapReadCallback resolves.
                 // deserialize the data update and apply
                 // it to the range (offset, offset + size) of allocation
                 // There could be nothing to be deserialized (if using shared memory)
                 // Needs to check potential offset/size OOB and overflow
-                // TODO(dawn:773): change to pure virtual after update on chromium side.
                 virtual bool DeserializeDataUpdate(const void* deserializePointer,
                                                    size_t deserializeSize,
                                                    size_t offset,
-                                                   size_t size) {
-                    return false;
-                }
-
-                // TODO(dawn:773): remove after update on chromium side.
-                virtual bool DeserializeInitialData(const void* deserializePointer,
-                                                    size_t deserializeSize,
-                                                    const void** data,
-                                                    size_t* dataLength) {
-                    return false;
-                }
+                                                   size_t size) = 0;
 
               private:
                 ReadHandle(const ReadHandle&) = delete;
@@ -158,40 +144,18 @@
                 // The data returned should be zero-initialized.
                 // The data returned must live at least until the WriteHandle is destructed.
                 // On failure, the pointer returned should be null.
-                // TODO(dawn:773): change to pure virtual after update on chromium side.
-                virtual void* GetData() {
-                    return nullptr;
-                }
+                virtual void* GetData() = 0;
 
                 // Get the required serialization size for SerializeDataUpdate
-                // TODO(dawn:773): change to pure virtual after update on chromium side.
-                virtual size_t SizeOfSerializeDataUpdate(size_t offset, size_t size) {
-                    return 0;
-                }
+                virtual size_t SizeOfSerializeDataUpdate(size_t offset, size_t size) = 0;
 
                 // Serialize a command to send the modified contents of
                 // the subrange (offset, offset + size) of the allocation at buffer unmap
                 // This subrange is always the whole mapped region for now
                 // There could be nothing to be serialized (if using shared memory)
-                // TODO(dawn:773): change to pure virtual after update on chromium side.
                 virtual void SerializeDataUpdate(void* serializePointer,
                                                  size_t offset,
-                                                 size_t size) {
-                }
-
-                // TODO(dawn:773): remove after update on chromium side.
-                virtual std::pair<void*, size_t> Open() {
-                    return std::make_pair(nullptr, 0);
-                }
-
-                // TODO(dawn:773): remove after update on chromium side.
-                virtual size_t SerializeFlushSize() {
-                    return 0;
-                }
-
-                // TODO(dawn:773): remove after update on chromium side.
-                virtual void SerializeFlush(void* serializePointer) {
-                }
+                                                 size_t size) = 0;
 
               private:
                 WriteHandle(const WriteHandle&) = delete;
diff --git a/src/include/dawn_wire/WireServer.h b/src/include/dawn_wire/WireServer.h
index bb3f7c2..3043a30 100644
--- a/src/include/dawn_wire/WireServer.h
+++ b/src/include/dawn_wire/WireServer.h
@@ -93,32 +93,16 @@
 
                 // Return the size of the command serialized if
                 // SerializeDataUpdate is called with the same offset/size args
-                // TODO(dawn:773): change to pure virtual after update on chromium side.
-                virtual size_t SizeOfSerializeDataUpdate(size_t offset, size_t size) {
-                    return 0;
-                }
+                virtual size_t SizeOfSerializeDataUpdate(size_t offset, size_t size) = 0;
 
                 // Gets called when a MapReadCallback resolves.
                 // Serialize the data update for the range (offset, offset + size) into
                 // |serializePointer| to the client There could be nothing to be serialized (if
                 // using shared memory)
-                // TODO(dawn:773): change to pure virtual after update on chromium side.
                 virtual void SerializeDataUpdate(const void* data,
                                                  size_t offset,
                                                  size_t size,
-                                                 void* serializePointer) {
-                }
-
-                // TODO(dawn:773): remove after update on chromium side.
-                virtual size_t SerializeInitialDataSize(const void* data, size_t dataLength) {
-                    return 0;
-                }
-
-                // TODO(dawn:773): remove after update on chromium side.
-                virtual void SerializeInitialData(const void* data,
-                                                  size_t dataLength,
-                                                  void* serializePointer) {
-                }
+                                                 void* serializePointer) = 0;
 
               private:
                 ReadHandle(const ReadHandle&) = delete;