Remove uses of external begin frame sources

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;
 }
@@ skipping 20 matching lines @@
       float page_scale,
       float top_controls_delta) = 0;
 
   // Notifies that the compositor has issed a BeginMainFrame.
   virtual void BeginMainFrame(double frame_time_sec) = 0;
 
   // Requests an OutputSurface to render into.
   virtual std::unique_ptr<cc::OutputSurface> CreateOutputSurface(
       bool fallback) = 0;
 
-  // Requests an external BeginFrameSource from the delegate.
-  virtual std::unique_ptr<cc::BeginFrameSource>
-  CreateExternalBeginFrameSource() = 0;
-
   // Notifies that the draw commands for a committed frame have been issued.
   virtual void DidCommitAndDrawCompositorFrame() = 0;
 
   // Notifies about a compositor frame commit operation having finished.
   virtual void DidCommitCompositorFrame() = 0;
 
   // Called by the compositor when page scale animation completed.
   virtual void DidCompletePageScaleAnimation() = 0;
 
   // Notifies that the compositor has posted a swapbuffers operation to the GPU
@@ skipping 34 matching lines @@
   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_