Implementing promise-based commit for driving OffscreenCanvas animations

third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef OffscreenCanvasRenderingContext2D_h
 #define OffscreenCanvasRenderingContext2D_h
 
 #include "core/html/canvas/CanvasContextCreationAttributes.h"
 #include "core/html/canvas/CanvasRenderingContext.h"
 #include "core/html/canvas/CanvasRenderingContextFactory.h"
@@ skipping 19 matching lines @@
         OffscreenCanvas* canvas,
         const CanvasContextCreationAttributes& attrs) override {
       return new OffscreenCanvasRenderingContext2D(scriptState, canvas, attrs);
     }
 
     CanvasRenderingContext::ContextType getContextType() const override {
       return CanvasRenderingContext::Context2d;
     }
   };
 
-  void commit(ScriptState*, ExceptionState&);
+  ScriptPromise commit(ScriptState*, ExceptionState&);
 
   // CanvasRenderingContext implementation
   ~OffscreenCanvasRenderingContext2D() override;
   ContextType getContextType() const override { return Context2d; }
   bool is2d() const override { return true; }
   void setOffscreenCanvasGetContextResult(OffscreenRenderingContext&) final;
   void setIsHidden(bool) final { ASSERT_NOT_REACHED(); }
   void stop() final { ASSERT_NOT_REACHED(); }
   void setCanvasGetContextResult(RenderingContext&) final {}
   void clearRect(double x, double y, double width, double height) override {
@@ skipping 43 matching lines @@
       const CanvasContextCreationAttributes& attrs);
   DECLARE_VIRTUAL_TRACE();
 
  private:
   bool m_needsMatrixClipRestore = false;
   std::unique_ptr<ImageBuffer> m_imageBuffer;
 
   bool isPaintable() const final;
 
   RefPtr<StaticBitmapImage> transferToStaticBitmapImage();
+  void doCommit(RefPtr<StaticBitmapImage>);

[xlai (Olivia), 2016/12/21 19:54:25]

I am confused that you add a function signature in header without adding its
implementation in cpp. Do I miss anything?

[Justin Novosad, 2016/12/21 21:15:40]

Good catch. This is unused. It is a leftover from something I tried earlier.
Done.

 };
 
 DEFINE_TYPE_CASTS(OffscreenCanvasRenderingContext2D,
                   CanvasRenderingContext,
                   context,
-                  context->is2d() && context->getOffscreenCanvas(),
-                  context.is2d() && context.getOffscreenCanvas());
+                  context->is2d() && context->offscreenCanvas(),
+                  context.is2d() && context.offscreenCanvas());
 
 }  // namespace blink
 
 #endif  // OffscreenCanvasRenderingContext2D_h