This CL implements the first draft of Canvas 2D Context Attributes, aka getContext('2d', { alpha: f…

Source/core/platform/graphics/chromium/Canvas2DLayerBridge.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 26 matching lines @@
 #include <public/Platform.h>
 #include <public/WebCompositorSupport.h>
 #include <public/WebGraphicsContext3D.h>
 
 using WebKit::WebExternalTextureLayer;
 using WebKit::WebGraphicsContext3D;
 using WebKit::WebTextureUpdater;
 
 namespace WebCore {
 
-Canvas2DLayerBridge::Canvas2DLayerBridge(PassRefPtr<GraphicsContext3D> context, const IntSize& size, ThreadMode threadMode, unsigned textureId)
+Canvas2DLayerBridge::Canvas2DLayerBridge(PassRefPtr<GraphicsContext3D> context, const IntSize& size, OpacityMode opacityMode, ThreadMode threadMode, unsigned textureId)
     : m_backBufferTexture(textureId)
     , m_size(size)
     , m_canvas(0)
     , m_context(context)
     , m_bytesAllocated(0)
     , m_didRecordDrawCommand(false)
     , m_framesPending(0)
     , m_next(0)
     , m_prev(0)
 {
     // Used by browser tests to detect the use of a Canvas2DLayerBridge.
     TRACE_EVENT_INSTANT0("test_gpu", "Canvas2DLayerBridgeCreation");
 
     m_layer = adoptPtr(WebKit::Platform::current()->compositorSupport()->createExternalTextureLayer(this));
     m_layer->setTextureId(textureId);
     m_layer->setRateLimitContext(threadMode == SingleThread);
+    m_layer->setOpaque(opacityMode == Opaque);
     GraphicsLayerChromium::registerContentsLayer(m_layer->layer());
 }
 
 Canvas2DLayerBridge::~Canvas2DLayerBridge()
 {
     GraphicsLayerChromium::unregisterContentsLayer(m_layer->layer());
     Canvas2DLayerManager::get().layerToBeDestroyed(this);
     if (m_canvas)
         m_canvas->setNotificationClient(0);
     m_layer->setTextureId(0);
@@ skipping 101 matching lines @@
 unsigned Canvas2DLayerBridge::backBufferTexture()
 {
     contextAcquired();
     if (m_canvas)
         m_canvas->flush();
     m_context->flush();
     return m_backBufferTexture;
 }
 
 }