Implement convertToBlob() in OffscreenCanvas

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

Index: third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.h
diff --git a/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.h b/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.h
index 070c7481438d00f44b73b018729306e4b6f51408..f1a98c99ddb69e9deeb9fd6539f2f20627fe01a8 100644
--- a/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.h
+++ b/third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.h
@@ -10,6 +10,7 @@
 #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"
@@ -61,6 +62,8 @@ class CORE_EXPORT OffscreenCanvas final
   // 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,
@@ -111,8 +114,6 @@ class CORE_EXPORT OffscreenCanvas final
   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