cc: Add initial GPU-to-GPU copy rasterizer implementation.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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 "content/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #if defined(OS_ANDROID)
@@ skipping 232 matching lines @@
             &max_unused_resource_memory_percentage)) {
       settings.max_unused_resource_memory_percentage =
           max_unused_resource_memory_percentage;
     }
   }
 
   settings.strict_layer_property_change_checking =
       cmd->HasSwitch(cc::switches::kStrictLayerPropertyChangeChecking);
 
   settings.use_map_image = RenderThreadImpl::current()->is_map_image_enabled();
+  settings.use_zero_copy = RenderThreadImpl::current()->is_zero_copy_enabled();
 
 #if defined(OS_ANDROID)
   settings.max_partial_texture_updates = 0;
   settings.scrollbar_animator = cc::LayerTreeSettings::LinearFade;
   settings.solid_color_scrollbar_color =
       (widget->UsingSynchronousRendererCompositor())  // It is Android Webview.
           ? SK_ColorTRANSPARENT
           : SkColorSetARGB(128, 128, 128, 128);
   settings.highp_threshold_min = 2048;
   // Android WebView handles root layer flings itself.
@@ skipping 387 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content