Revert "[metal] Add Dawn toggle and Tint option for TensorsOps"

This reverts commit 2a005ba4ce42b2d473b107fe25f1cfc48a3e6e2c.

Reason for revert: Causing Dawn->Chromium roller failure. Error on ios-simulator.

Failure Link: https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket/8672287040021697281/+/u/compile__with_patch_/raw_io.output_text_failure_summary_

Original change's description:
> [metal] Add Dawn toggle and Tint option for TensorsOps
>
> Expose 32x32x32 for F16 as the only configuration for now.
>
> Bug: 550350271
> Change-Id: I592707d5168e5342587435718ec71bb838f0ddd0
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/337135
> Reviewed-by: Alan Baker <alanbaker@google.com>
> Commit-Queue: James Price <jrprice@google.com>

TBR=jrprice@google.com,alanbaker@google.com,dawn-scoped@luci-project-accounts.iam.gserviceaccount.com

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 550350271
Change-Id: I1b0147f9a9e2337b7dc39bf2cccce698f2bac5f3
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/337255
Reviewed-by: James Price <jrprice@google.com>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Commit-Queue: James Price <jrprice@google.com>
diff --git a/src/dawn/native/Toggles.cpp b/src/dawn/native/Toggles.cpp
index 421dcdf..9b7acbb 100644
--- a/src/dawn/native/Toggles.cpp
+++ b/src/dawn/native/Toggles.cpp
@@ -838,9 +838,6 @@
       "Disable clamping of subgroupMatrixLoad/Store on storage buffers if "
       "cooperativeMatrixRobustBufferAccess == VK_TRUE",
       "https://crbug.com/548005877", ToggleStage::Device}},
-    {Toggle::MetalEnableTensors,
-     {"metal_enable_tensors", "Enable the use of Metal 4 Tensor Operations for subgroup matrix.",
-      "https://crbug.com/550350271", ToggleStage::Adapter}},
     {Toggle::WaitIsThreadSafe,
      {"wait_is_thread_safe",
       "WaitFor* functions are thread-safe and can be called without the device-lock if implicit "
diff --git a/src/dawn/native/Toggles.h b/src/dawn/native/Toggles.h
index 9d9a9dc..40892c6 100644
--- a/src/dawn/native/Toggles.h
+++ b/src/dawn/native/Toggles.h
@@ -199,7 +199,6 @@
     VulkanDisallowNPOTDepthStencilMipmaps,
     VulkanReplaceUnsignedCompareZero,
     VulkanUseCooperativeMatrixRobustBufferAccess,
-    MetalEnableTensors,
 
     // Once all backends have been updated to be thread safe for waiting, we can remove this toggle.
     WaitIsThreadSafe,
diff --git a/src/dawn/native/metal/PhysicalDeviceMTL.mm b/src/dawn/native/metal/PhysicalDeviceMTL.mm
index 65488b8..47e4e35 100644
--- a/src/dawn/native/metal/PhysicalDeviceMTL.mm
+++ b/src/dawn/native/metal/PhysicalDeviceMTL.mm
@@ -385,15 +385,7 @@
 }
 
 void PhysicalDevice::SetupBackendAdapterToggles(dawn::platform::Platform* platform,
-                                                TogglesState* adapterToggles) const {
-    if (@available(macos 26.0, *)) {
-        if (![*mDevice supportsFamily:MTLGPUFamilyMetal4]) {
-            adapterToggles->ForceSet(Toggle::MetalEnableTensors, false);
-        }
-    } else {
-        adapterToggles->ForceSet(Toggle::MetalEnableTensors, false);
-    }
-}
+                                                TogglesState* adapterToggles) const {}
 
 void PhysicalDevice::SetupBackendDeviceToggles(dawn::platform::Platform* platform,
                                                TogglesState* deviceToggles) const {
@@ -1069,41 +1061,23 @@
         }
     }
     if (auto* subgroupMatrixConfigs = info.Get<AdapterPropertiesSubgroupMatrixConfigs>()) {
-        if (toggles.IsEnabled(Toggle::MetalEnableTensors)) {
-            if (@available(macos 26.0, *)) {
-                DAWN_ASSERT([*mDevice supportsFamily:MTLGPUFamilyMetal4]);
-            } else {
-                DAWN_ASSERT(false);
-            }
+        DAWN_ASSERT([*mDevice supportsFamily:MTLGPUFamilyApple7]);
 
-            // TODO(553457823): decide which other matrix configurations to expose.
-            auto configs = HeapArray<SubgroupMatrixConfig>(1);
-            configs[0].componentType = wgpu::SubgroupMatrixComponentType::F16;
-            configs[0].resultComponentType = wgpu::SubgroupMatrixComponentType::F16;
-            configs[0].M = 32;
-            configs[0].N = 32;
-            configs[0].K = 32;
+        auto configs = HeapArray<SubgroupMatrixConfig>(2);
 
-            subgroupMatrixConfigs->configs = std::move(configs).MoveToSpan();
-        } else {
-            DAWN_ASSERT([*mDevice supportsFamily:MTLGPUFamilyApple7]);
+        configs[0].componentType = wgpu::SubgroupMatrixComponentType::F32;
+        configs[0].resultComponentType = wgpu::SubgroupMatrixComponentType::F32;
+        configs[0].M = 8;
+        configs[0].N = 8;
+        configs[0].K = 8;
 
-            auto configs = HeapArray<SubgroupMatrixConfig>(2);
+        configs[1].componentType = wgpu::SubgroupMatrixComponentType::F16;
+        configs[1].resultComponentType = wgpu::SubgroupMatrixComponentType::F16;
+        configs[1].M = 8;
+        configs[1].N = 8;
+        configs[1].K = 8;
 
-            configs[0].componentType = wgpu::SubgroupMatrixComponentType::F32;
-            configs[0].resultComponentType = wgpu::SubgroupMatrixComponentType::F32;
-            configs[0].M = 8;
-            configs[0].N = 8;
-            configs[0].K = 8;
-
-            configs[1].componentType = wgpu::SubgroupMatrixComponentType::F16;
-            configs[1].resultComponentType = wgpu::SubgroupMatrixComponentType::F16;
-            configs[1].M = 8;
-            configs[1].N = 8;
-            configs[1].K = 8;
-
-            subgroupMatrixConfigs->configs = std::move(configs).MoveToSpan();
-        }
+        subgroupMatrixConfigs->configs = std::move(configs).MoveToSpan();
     }
 }
 }  // namespace dawn::native::metal
diff --git a/src/dawn/native/metal/ShaderModuleMTL.mm b/src/dawn/native/metal/ShaderModuleMTL.mm
index 4b95323..ba12a99 100644
--- a/src/dawn/native/metal/ShaderModuleMTL.mm
+++ b/src/dawn/native/metal/ShaderModuleMTL.mm
@@ -374,7 +374,6 @@
 
     req.tintOptions.extensions.disable_demote_to_helper =
         device->IsToggleEnabled(Toggle::DisableDemoteToHelper);
-    req.tintOptions.extensions.enable_tensors = device->IsToggleEnabled(Toggle::MetalEnableTensors);
 
     req.limits = LimitsForCompilationRequest::Create(device->GetLimits().v1);
     req.adapterSupportedLimits = UnsafeUnserializedValue(
diff --git a/src/tint/cmd/tint/main.cc b/src/tint/cmd/tint/main.cc
index c4363d3..ed2e4ba 100644
--- a/src/tint/cmd/tint/main.cc
+++ b/src/tint/cmd/tint/main.cc
@@ -179,8 +179,6 @@
     std::unordered_map<uint32_t, tint::msl::writer::ArgumentBufferInfo>
         group_to_argument_buffer_info;
 
-    bool enable_tensors = false;
-
     std::unordered_map<uint32_t, uint32_t> pixel_local_attachments;
     tint::msl::validate::MslVersion msl_version = tint::msl::validate::MslVersion::kMsl_2_3;
 #endif
@@ -521,10 +519,6 @@
         "dynamic-offset",
         R"(Mapping for dynamic buffers to be attached to the entry point, format is GROUP.BINDING=OFFSET, comma separated. BINDING is the BindingIndex, not @binding BindingNumber))");
 
-    auto& enable_tensors = options.Add<BoolOption>(
-        "enable-tensors", "Enable Metal 4 tensor operations in MSL", Default{false});
-    TINT_DEFER(opts->enable_tensors = *enable_tensors.value);
-
     // Default to validating against MSL 2.3, which corresponds to macOS 11.0.
     tint::Vector<EnumName<tint::msl::validate::MslVersion>, 2> msl_version_enum_names{
         EnumName(tint::msl::validate::MslVersion::kMsl_2_3, "2.3"),
@@ -1216,7 +1210,6 @@
     gen_options.use_argument_buffers = options.use_argument_buffers;
     gen_options.group_to_argument_buffer_info = options.group_to_argument_buffer_info;
     gen_options.array_length_from_constants = GenerateArrayLengthFromConstants(ir, options.ep_name);
-    gen_options.extensions.enable_tensors = options.enable_tensors;
 
     auto entry_point = inspector.GetEntryPoint(options.ep_name);
     gen_options.non_constant_zero_offset = tint::RoundUp(4U, entry_point.immediate_data_size);
diff --git a/src/tint/lang/msl/writer/common/options.h b/src/tint/lang/msl/writer/common/options.h
index 2adf427..9dc8812 100644
--- a/src/tint/lang/msl/writer/common/options.h
+++ b/src/tint/lang/msl/writer/common/options.h
@@ -162,11 +162,7 @@
         /// Set to `true` to disable demote to helper transform
         bool disable_demote_to_helper = false;
 
-        /// Set to `true` to enable the use of Metal Tensors for subgroup matrix.
-        /// TODO(553457231): Enable in fuzzers when implementation is complete.
-        bool enable_tensors = false;
-
-        TINT_REFLECT(Extensions, disable_demote_to_helper, enable_tensors);
+        TINT_REFLECT(Extensions, disable_demote_to_helper);
         TINT_REFLECT_HASH_CODE(Extensions);
 
         bool operator==(const Extensions&) const = default;