cc: Make OutputSurface::BindToClient pure virtual and not return bool

content/browser/compositor/mus_browser_compositor_output_surface.h

 // Copyright 2016 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_BROWSER_COMPOSITOR_MUS_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 #define CONTENT_BROWSER_COMPOSITOR_MUS_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 23 matching lines @@
       scoped_refptr<ui::CompositorVSyncManager> vsync_manager,
       cc::SyntheticBeginFrameSource* begin_frame_source,
       std::unique_ptr<display_compositor::CompositorOverlayCandidateValidator>
           overlay_candidate_validator);
 
   ~MusBrowserCompositorOutputSurface() override;
 
  protected:
   // cc::OutputSurface implementation.
   void SwapBuffers(cc::OutputSurfaceFrame frame) override;
-  bool BindToClient(cc::OutputSurfaceClient* client) override;
 
   // cc::CompositorFrameSinkClient:
   void SetBeginFrameSource(cc::BeginFrameSource* source) override;
   void ReclaimResources(const cc::ReturnedResourceArray& resources) override;
   void SetTreeActivationCallback(const base::Closure& callback) override;
   void DidReceiveCompositorFrameAck() override;
   void DidLoseCompositorFrameSink() override;
   void OnDraw(const gfx::Transform& transform,
               const gfx::Rect& viewport,
               bool resourceless_software_draw) override;
@@ skipping 11 matching lines @@
   std::unique_ptr<ui::WindowCompositorFrameSink> ui_compositor_frame_sink_;
   std::vector<uint32_t> free_resource_ids_;
   std::vector<gpu::Mailbox> mailboxes_;
 
   DISALLOW_COPY_AND_ASSIGN(MusBrowserCompositorOutputSurface);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_MUS_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_