Use surface copy requests for layout tests.

content/renderer/render_widget.h

 // Copyright (c) 2012 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_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 186 matching lines @@
   void DidCompletePageScaleAnimation() override;
   void DidCompleteSwapBuffers() override;
   void ForwardCompositorProto(const std::vector<uint8_t>& proto) override;
   bool IsClosing() const override;
   void OnSwapBuffersAborted() override;
   void OnSwapBuffersComplete() override;
   void OnSwapBuffersPosted() override;
   void RequestScheduleAnimation() override;
   void UpdateVisualState() override;
   void WillBeginCompositorFrame() override;
+  std::unique_ptr<cc::SwapPromise> RequestCopyOfOutputForLayoutTest(
+      std::unique_ptr<cc::CopyOutputRequest> request) override;
 
   // RenderWidgetInputHandlerDelegate
   void FocusChangeComplete() override;
   bool HasTouchEventHandlersAt(const gfx::Point& point) const override;
   void ObserveGestureEventAndResult(const blink::WebGestureEvent& gesture_event,
                                     const gfx::Vector2dF& unused_delta,
                                     bool event_processed) override;
 
   void OnDidHandleKeyEvent() override;
   void OnDidOverscroll(const DidOverscrollParams& params) override;
@@ skipping 564 matching lines @@
   // This reference is set by the RenderFrame and is used to query the IME-
   // related state from the plugin to later send to the browser.
   PepperPluginInstanceImpl* focused_pepper_plugin_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_