Use surface copy requests for layout tests.

content/renderer/gpu/render_widget_compositor_delegate.h

 // 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.
 
 #ifndef CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_DELEGATE_H_
 #define CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_DELEGATE_H_
 
 namespace blink {
 class WebWidget;
 struct WebScreenInfo;
 }
 
 namespace cc {
 class BeginFrameSource;
+class CopyOutputRequest;
 class OutputSurface;
+class SwapPromise;
 }
 
 namespace content {
 
 // Consumers of RenderWidgetCompositor implement this delegate in order to
 // transport compositing information across processes.
 class CONTENT_EXPORT RenderWidgetCompositorDelegate {
  public:
   // Report viewport related properties during a commit from the compositor
   // thread.
@@ skipping 50 matching lines @@
 
   // Requests a visual frame-based update to the state of the delegate if there
   // an update available.
   virtual void UpdateVisualState() = 0;
 
   // Indicates that the compositor is about to begin a frame. This is primarily
   // to signal to flow control mechanisms that a frame is beginning, not to
   // perform actual painting work.
   virtual void WillBeginCompositorFrame() = 0;
 
+  // For use in layout test mode only, attempts to copy the full content of the
+  // compositor.
+  virtual std::unique_ptr<cc::SwapPromise> RequestCopyOfOutputForLayoutTest(
+      std::unique_ptr<cc::CopyOutputRequest> request) = 0;
+
  protected:
   virtual ~RenderWidgetCompositorDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_DELEGATE_H_