WebGPU: Expose GPUAdapter.extensions in Blink

This patch exposes the read-only attribute GPUAdapter.extensions in
Blink as is required in WebGPU SPEC. GPUAdapter.extensions is a
dictionary whose keys are extension names and values are boolean values
that indicate if the extensions are supported on this adapter or not.

BUG=chromium:996713

Change-Id: I6bfd2283babf981208ade10adb458f088f0333f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1929717Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
Cr-Commit-Position: refs/heads/master@{#718409}

third_party/blink/renderer/modules/webgpu/gpu_adapter.cc

@@ -5,6 +5,7 @@
 #include "third_party/blink/renderer/modules/webgpu/gpu_adapter.h"
 
 #include "third_party/blink/renderer/bindings/core/v8/script_promise_resolver.h"
+#include "third_party/blink/renderer/bindings/core/v8/v8_object_builder.h"
 #include "third_party/blink/renderer/modules/webgpu/gpu_device.h"
 #include "third_party/blink/renderer/modules/webgpu/gpu_request_adapter_options.h"
 
@@ -25,14 +26,21 @@ GPUAdapter::GPUAdapter(
     uint32_t adapter_service_id,
     const WGPUDeviceProperties& properties,
     scoped_refptr<DawnControlClientHolder> dawn_control_client)
-    : DawnObjectBase(dawn_control_client), name_(name) {
-  // TODO(jiawei.shao@intel.com): add GPUExtensions as a member of GPUAdapter
-}
+    : DawnObjectBase(dawn_control_client),
+      name_(name),
+      adapter_properties_(properties) {}
 
 const String& GPUAdapter::name() const {
   return name_;
 }
 
+ScriptValue GPUAdapter::extensions(ScriptState* script_state) const {
+  V8ObjectBuilder object_builder(script_state);
+  object_builder.AddBoolean("textureCompressionBC",
+                            adapter_properties_.textureCompressionBC);
+  return object_builder.GetScriptValue();
+}
+
 // TODO(jiawei.shao@intel.com) request device with adapter_server_id
 ScriptPromise GPUAdapter::requestDevice(ScriptState* script_state,
                                         const GPUDeviceDescriptor* descriptor) {

third_party/blink/renderer/modules/webgpu/gpu_adapter.h

@@ -32,12 +32,14 @@ class GPUAdapter final : public ScriptWrappable, public DawnObjectBase {
              scoped_refptr<DawnControlClientHolder> dawn_control_client);
 
   const String& name() const;
+  ScriptValue extensions(ScriptState* script_state) const;
 
   ScriptPromise requestDevice(ScriptState* script_state,
                               const GPUDeviceDescriptor* descriptor);
 
  private:
   String name_;
+  WGPUDeviceProperties adapter_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(GPUAdapter);
 };

third_party/blink/renderer/modules/webgpu/gpu_adapter.idl

@@ -8,6 +8,7 @@
     Exposed(Window WebGPU, Worker WebGPU)
 ] interface GPUAdapter {
     readonly attribute DOMString name;
+    [CallWith=ScriptState, SameObject] readonly attribute object extensions;
 
     [CallWith=ScriptState] Promise<GPUDevice> requestDevice(optional GPUDeviceDescriptor descriptor = {});
 };