Reland Submit Compositor Frame from OffscreenCanvas on main

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

 // 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.
 
 #include "modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h"
 
 #include "bindings/modules/v8/OffscreenCanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContext.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/Settings.h"
 #include "core/workers/WorkerGlobalScope.h"
@@ skipping 26 matching lines @@
     if (workerSettings && workerSettings->disableReadingFromCanvas())
         canvas->setDisableReadingFromCanvasTrue();
 }
 
 DEFINE_TRACE(OffscreenCanvasRenderingContext2D)
 {
     CanvasRenderingContext::trace(visitor);
     BaseRenderingContext2D::trace(visitor);
 }
 
+void OffscreenCanvasRenderingContext2D::commit(ExecutionContext* executionContext)
+{
+    if (executionContext->isWorkerGlobalScope()) {
+        // TODO(xlai): implement commit() on worker thread; currently, do
+        // nothing for worker thread. See crbug.com/563858.
+        return;
+    }
+    getOffscreenCanvas()->getOrCreateFrameDispatcher()->dispatchFrame();
+}
+
 // BaseRenderingContext2D implementation
 bool OffscreenCanvasRenderingContext2D::originClean() const
 {
     return getOffscreenCanvas()->originClean();
 }
 
 void OffscreenCanvasRenderingContext2D::setOriginTainted()
 {
     return getOffscreenCanvas()->setOriginTainted();
 }
@@ skipping 144 matching lines @@
 bool OffscreenCanvasRenderingContext2D::isContextLost() const
 {
     return false;
 }
 
 bool OffscreenCanvasRenderingContext2D::isPaintable() const
 {
     return this->imageBuffer();
 }
 }