Implement convertToBlob() in OffscreenCanvas

third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.h

 // Copyright 2015 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 OffscreenCanvas_h
 #define OffscreenCanvas_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/canvas/CanvasImageSource.h"
+#include "core/offscreencanvas/ImageEncodeOptions.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/graphics/OffscreenCanvasFrameDispatcher.h"
 #include "platform/heap/Handle.h"
 #include <memory>
 
 namespace blink {
 
 class CanvasContextCreationAttributes;
 class ImageBitmap;
 class
@@ skipping 31 matching lines @@
   CanvasRenderingContext* renderingContext() { return m_context; }
 
   static void registerRenderingContextFactory(
       std::unique_ptr<CanvasRenderingContextFactory>);
 
   bool originClean() const;
   void setOriginTainted() { m_originClean = false; }
   // TODO(crbug.com/630356): apply the flag to WebGL context as well
   void setDisableReadingFromCanvasTrue() { m_disableReadingFromCanvas = true; }
 
+  bool isPaintable() const;
+
   OffscreenCanvasFrameDispatcher* getOrCreateFrameDispatcher();
 
   void setSurfaceId(uint32_t clientId,
                     uint32_t sinkId,
                     uint32_t localId,
                     uint64_t nonce) {
     m_clientId = clientId;
     m_sinkId = sinkId;
     m_localId = localId;
     m_nonce = nonce;
@@ skipping 30 matching lines @@
 
   Member<CanvasRenderingContext> m_context;
   int m_canvasId = -1;  // DOMNodeIds starts from 0, using -1 to indicate no
                         // associated canvas element.
   IntSize m_size;
   bool m_isNeutered = false;
 
   bool m_originClean;
   bool m_disableReadingFromCanvas = false;
 
-  bool isPaintable() const;
-
   std::unique_ptr<OffscreenCanvasFrameDispatcher> m_frameDispatcher;
   // cc::SurfaceId is broken into three integer components as this can be used
   // in transfer of OffscreenCanvas across threads
   // If this object is not created via
   // HTMLCanvasElement.transferControlToOffscreen(),
   // then the following members would remain as initialized zero values.
   uint32_t m_clientId = 0;
   uint32_t m_sinkId = 0;
   uint32_t m_localId = 0;
   uint64_t m_nonce = 0;
 };
 
 }  // namespace blink
 
 #endif  // OffscreenCanvas_h