Add stubs for WebGPU's CanvasRenderingContext

This makes canvas.getContext("gpupresent") return a GPUCanvasContext
when the --enable-unsafe-webgpu flag is present.

BUG=chromium:877147

Change-Id: I74b35cf117aadcc00a979189b8364798b353ac66
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1559181Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#650595}

third_party/blink/renderer/bindings/scripts/utilities.py

@@ -445,9 +445,9 @@ def shorten_union_name(union_type):
         'CSSImageValueOrHTMLImageElementOrSVGImageElementOrHTMLVideoElementOrHTMLCanvasElementOrImageBitmapOrOffscreenCanvas': 'CanvasImageSource',
         # modules/canvas/htmlcanvas/html_canvas_element_module_support_webgl2_compute.idl
         # Due to html_canvas_element_module_support_webgl2_compute.idl and html_canvas_element_module.idl are exclusive in modules_idl_files.gni, they have same shorten name.
-        'CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrWebGL2ComputeRenderingContextOrImageBitmapRenderingContextOrXRPresentationContext': 'RenderingContext',
+        'CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrWebGL2ComputeRenderingContextOrImageBitmapRenderingContextOrXRPresentationContextOrGPUCanvasContext': 'RenderingContext',
         # modules/canvas/htmlcanvas/html_canvas_element_module.idl
-        'CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContextOrXRPresentationContext': 'RenderingContext',
+        'CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContextOrXRPresentationContextOrGPUCanvasContext': 'RenderingContext',
         # core/frame/window_or_worker_global_scope.idl
         'HTMLImageElementOrSVGImageElementOrHTMLVideoElementOrHTMLCanvasElementOrBlobOrImageDataOrImageBitmapOrOffscreenCanvas': 'ImageBitmapSource',
         # bindings/tests/idls/core/TestTypedefs.idl

third_party/blink/renderer/core/html/canvas/canvas_rendering_context.cc

@@ -148,6 +148,8 @@ CanvasRenderingContext::ContextType CanvasRenderingContext::ContextTypeFromId(
     return kContextImageBitmap;
   if (id == "xrpresent")
     return kContextXRPresent;
+  if (id == "gpupresent" && RuntimeEnabledFeatures::WebGPUEnabled())
+    return kContextGPUPresent;
   return kContextTypeUnknown;
 }
 

third_party/blink/renderer/core/html/canvas/canvas_rendering_context.h

@@ -71,7 +71,8 @@ class CORE_EXPORT CanvasRenderingContext : public ScriptWrappable,
     kContextImageBitmap = 5,
     kContextXRPresent = 6,
     kContextWebgl2Compute = 7,
-    kContextTypeUnknown = 8,
+    kContextGPUPresent = 8,
+    kContextTypeUnknown = 9,
     kMaxValue = kContextTypeUnknown,
   };
 

third_party/blink/renderer/core/html/canvas/html_canvas_element.h

@@ -75,13 +75,13 @@ class IntSize;
 
 #if defined(SUPPORT_WEBGL2_COMPUTE_CONTEXT)
 class
-    CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrWebGL2ComputeRenderingContextOrImageBitmapRenderingContextOrXRPresentationContext;
-typedef CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrWebGL2ComputeRenderingContextOrImageBitmapRenderingContextOrXRPresentationContext
+    CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrWebGL2ComputeRenderingContextOrImageBitmapRenderingContextOrXRPresentationContextOrGPUCanvasContext;
+typedef CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrWebGL2ComputeRenderingContextOrImageBitmapRenderingContextOrXRPresentationContextOrGPUCanvasContext
     RenderingContext;
 #else
 class
-    CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContextOrXRPresentationContext;
-typedef CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContextOrXRPresentationContext
+    CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContextOrXRPresentationContextOrGPUCanvasContext;
+typedef CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContextOrXRPresentationContextOrGPUCanvasContext
     RenderingContext;
 #endif
 

third_party/blink/renderer/modules/canvas/htmlcanvas/html_canvas_element_module.idl

@@ -8,7 +8,8 @@ typedef (CanvasRenderingContext2D or
          WebGLRenderingContext or
          WebGL2RenderingContext or
          ImageBitmapRenderingContext or
-         XRPresentationContext) RenderingContext;
+         XRPresentationContext or
+         GPUCanvasContext) RenderingContext;
 
 [
     ImplementedAs=HTMLCanvasElementModule

third_party/blink/renderer/modules/canvas/htmlcanvas/html_canvas_element_module_support_webgl2_compute.idl

@@ -9,7 +9,8 @@ typedef (CanvasRenderingContext2D or
          WebGL2RenderingContext or
          WebGL2ComputeRenderingContext or
          ImageBitmapRenderingContext or
-         XRPresentationContext) RenderingContext;
+         XRPresentationContext or
+         GPUCanvasContext) RenderingContext;
 
 [
     ImplementedAs=HTMLCanvasElementModule

third_party/blink/renderer/modules/modules_initializer.cc

@@ -87,6 +87,7 @@
 #include "third_party/blink/renderer/modules/accessibility/inspector_accessibility_agent.h"
 #include "third_party/blink/renderer/modules/webgl/webgl2_rendering_context.h"
 #include "third_party/blink/renderer/modules/webgl/webgl_rendering_context.h"
+#include "third_party/blink/renderer/modules/webgpu/gpu_canvas_context.h"
 #include "third_party/blink/renderer/modules/xr/xr_presentation_context.h"
 #include "third_party/blink/renderer/platform/cross_thread_functional.h"
 #include "third_party/blink/renderer/platform/mojo/mojo_helper.h"
@@ -140,6 +141,8 @@ void ModulesInitializer::Initialize() {
       std::make_unique<ImageBitmapRenderingContext::Factory>());
   HTMLCanvasElement::RegisterRenderingContextFactory(
       std::make_unique<XRPresentationContext::Factory>());
+  HTMLCanvasElement::RegisterRenderingContextFactory(
+      std::make_unique<GPUCanvasContext::Factory>());
 
   // OffscreenCanvas context types must be registered with the OffscreenCanvas.
   OffscreenCanvas::RegisterRenderingContextFactory(

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

@@ -4,4 +4,37 @@
 
 #include "third_party/blink/renderer/modules/webgpu/gpu_canvas_context.h"
 
-namespace blink {}  // namespace blink
+#include "third_party/blink/renderer/bindings/modules/v8/rendering_context.h"
+
+namespace blink {
+
+GPUCanvasContext::Factory::Factory() {}
+GPUCanvasContext::Factory::~Factory() {}
+
+CanvasRenderingContext* GPUCanvasContext::Factory::Create(
+    CanvasRenderingContextHost* host,
+    const CanvasContextCreationAttributesCore& attrs) {
+  return MakeGarbageCollected<GPUCanvasContext>(host, attrs);
+}
+
+CanvasRenderingContext::ContextType GPUCanvasContext::Factory::GetContextType()
+    const {
+  return CanvasRenderingContext::kContextGPUPresent;
+}
+
+GPUCanvasContext::GPUCanvasContext(
+    CanvasRenderingContextHost* host,
+    const CanvasContextCreationAttributesCore& attrs)
+    : CanvasRenderingContext(host, attrs) {}
+
+GPUCanvasContext::~GPUCanvasContext() {}
+
+CanvasRenderingContext::ContextType GPUCanvasContext::GetContextType() const {
+  return CanvasRenderingContext::kContextGPUPresent;
+}
+
+void GPUCanvasContext::SetCanvasGetContextResult(RenderingContext& result) {
+  result.SetGPUCanvasContext(this);
+}
+
+}  // namespace blink

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

@@ -5,14 +5,55 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBGPU_GPU_CANVAS_CONTEXT_H_
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBGPU_GPU_CANVAS_CONTEXT_H_
 
+#include "third_party/blink/renderer/core/html/canvas/canvas_rendering_context.h"
+#include "third_party/blink/renderer/core/html/canvas/canvas_rendering_context_factory.h"
 #include "third_party/blink/renderer/platform/bindings/script_wrappable.h"
+#include "third_party/blink/renderer/platform/graphics/static_bitmap_image.h"
 
 namespace blink {
 
-class GPUCanvasContext : public ScriptWrappable {
+// A GPUCanvasContext does little by itself and basically just binds a canvas
+// and a GPUSwapChain together and forwards calls from one to the other. The
+// logic that are in other CanvasRenderingContext is in GPUSwapChain instead.
+class GPUCanvasContext : public CanvasRenderingContext {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
+  class Factory : public CanvasRenderingContextFactory {
+    DISALLOW_COPY_AND_ASSIGN(Factory);
+
+   public:
+    Factory();
+    ~Factory() override;
+
+    CanvasRenderingContext* Create(
+        CanvasRenderingContextHost*,
+        const CanvasContextCreationAttributesCore&) override;
+    CanvasRenderingContext::ContextType GetContextType() const override;
+  };
+
+  GPUCanvasContext(CanvasRenderingContextHost*,
+                   const CanvasContextCreationAttributesCore&);
+  ~GPUCanvasContext() override;
+
+  // CanvasRenderingContext implementation
+  ContextType GetContextType() const override;
+  void SetCanvasGetContextResult(RenderingContext&) final;
+  scoped_refptr<StaticBitmapImage> GetImage(AccelerationHint) const final {
+    return nullptr;
+  }
+  void SetIsHidden(bool) override {}
+  bool isContextLost() const override { return false; }
+  bool IsComposited() const final { return true; }
+  bool IsAccelerated() const final { return true; }
+  bool IsOriginTopLeft() const final { return true; }
+  bool Is3d() const final { return true; }
+  void SetFilterQuality(SkFilterQuality) final {}
+  bool IsPaintable() const final { return true; }
+  int ExternallyAllocatedBufferCountPerPixel() final { return 1; }
+  void Stop() override {}
+  cc::Layer* CcLayer() const final { return nullptr; }
+
   // gpu_canvas_context.idl
   // TODO(crbug.com/877147): implement GPUCanvasContext.
 
@@ -20,6 +61,14 @@ class GPUCanvasContext : public ScriptWrappable {
   DISALLOW_COPY_AND_ASSIGN(GPUCanvasContext);
 };
 
+DEFINE_TYPE_CASTS(GPUCanvasContext,
+                  CanvasRenderingContext,
+                  context,
+                  context->GetContextType() ==
+                      CanvasRenderingContext::kContextGPUPresent,
+                  context.GetContextType() ==
+                      CanvasRenderingContext::kContextGPUPresent);
+
 }  // namespace blink
 
 #endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_WEBGPU_GPU_CANVAS_CONTEXT_H_

third_party/blink/web_tests/FlagExpectations/enable-unsafe-webgpu

 # WebGPU tests are only run with --enable-unsafe-webgpu
+Bug(none) webgpu/canvas_context.html [ Pass ]
 Bug(none) webgpu/fence.html [ Pass ]

third_party/blink/web_tests/TestExpectations

@@ -12,6 +12,7 @@ Bug(intentional) external/wpt/infrastructure/reftest/reftest_timeout.html [ Time
 Bug(intentional) external/wpt/infrastructure/expected-fail/timeout.html [ Timeout ]
 
 # WebGPU tests are only run with --enable-unsafe-webgpu
+Bug(none) webgpu/canvas_context.html [ Skip ]
 Bug(none) webgpu/fence.html [ Skip ]
 
 crbug.com/807686 crbug.com/24182 jquery/manipulation.html [ Timeout Pass ]

third_party/blink/web_tests/webgpu/canvas_context.html

+<!DOCTYPE html>
+<script src="../resources/testharness.js"></script>
+<script src="../resources/testharnessreport.js"></script>
+<script>
+let width = 10;
+let height = 10;
+
+test(function() {
+  let canvas = document.createElement("canvas");
+  canvas.width = width;
+  canvas.height = height;
+
+  let ctx = canvas.getContext('gpupresent');
+  assert_true(ctx instanceof GPUCanvasContext);
+}, "Test that canvas.getContext('gpupresent') returns an instance of GPUCanvasContext");
+
+</script>