Update Resize information from OffscreenCanvas to OffscreenCanvasFrameDispatcher

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

 // 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.
 
 #include "core/offscreencanvas/OffscreenCanvas.h"
 
 #include "core/dom/ExceptionCode.h"
 #include "core/fileapi/Blob.h"
 #include "core/html/ImageData.h"
 #include "core/html/canvas/CanvasAsyncBlobCreator.h"
@@ skipping 24 matching lines @@
   setSize(newSize);
 }
 
 void OffscreenCanvas::setHeight(unsigned height) {
   IntSize newSize = m_size;
   newSize.setHeight(clampTo<int>(height));
   setSize(newSize);
 }
 
 void OffscreenCanvas::setSize(const IntSize& size) {
+  if (size == m_size)
+    return;
   if (m_context) {
     if (m_context->is3d()) {
       if (size != m_size)
         m_context->reshape(size.width(), size.height());
     } else if (m_context->is2d()) {
       m_context->reset();
     }
   }
   m_size = size;
+  if (m_frameDispatcher) {
+    m_frameDispatcher->reshape(width(), height());

[xidachen, 2016/11/22 18:41:45]

As discussed offline, please change this to use m_size.width() and
m_size.height(), so that we are passing int, and we can avoid conversion from
int-->unsigned-->int round trip.

+  }
 }
 
 void OffscreenCanvas::setNeutered() {
   ASSERT(!m_context);
   m_isNeutered = true;
   m_size.setWidth(0);
   m_size.setHeight(0);
 }
 
 ImageBitmap* OffscreenCanvas::transferToImageBitmap(
@@ skipping 171 matching lines @@
   return resolver->promise();
 }
 
 DEFINE_TRACE(OffscreenCanvas) {
   visitor->trace(m_context);
   visitor->trace(m_executionContext);
   EventTarget::trace(visitor);
 }
 
 }  // namespace blink