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

services/ui/surfaces/direct_output_surface_ozone.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 SERVICES_UI_SURFACES_DIRECT_OUTPUT_SURFACE_OZONE_H_
 #define SERVICES_UI_SURFACES_DIRECT_OUTPUT_SURFACE_OZONE_H_
 
 #include <memory>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 35 matching lines @@
       gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
       uint32_t target,
       uint32_t internalformat);
 
   ~DirectOutputSurfaceOzone() override;
 
   // TODO(rjkroege): Implement the equivalent of Reflector.
 
  private:
   // cc::OutputSurface implementation.
-  bool BindToClient(cc::OutputSurfaceClient* client) override;
+  void BindToClient(cc::OutputSurfaceClient* client) override;
   void EnsureBackbuffer() override;
   void DiscardBackbuffer() override;
   void BindFramebuffer() override;
   void Reshape(const gfx::Size& size,
                float device_scale_factor,
                const gfx::ColorSpace& color_space,
                bool has_alpha) override;
   void SwapBuffers(cc::OutputSurfaceFrame frame) override;
   uint32_t GetFramebufferCopyTextureFormat() override;
   cc::OverlayCandidateValidator* GetOverlayCandidateValidator() const override;
   bool IsDisplayedAsOverlayPlane() const override;
   unsigned GetOverlayTextureId() const override;
   bool SurfaceIsSuspendForRecycle() const override;
   bool HasExternalStencilTest() const override;
   void ApplyExternalStencil() override;
 
   // Taken from BrowserCompositor specific API.
   void OnUpdateVSyncParametersFromGpu(base::TimeTicks timebase,
                                       base::TimeDelta interval);
 
   // Called when a swap completion is sent from the GPU process.
   void OnGpuSwapBuffersCompleted(gfx::SwapResult result);
 
+  cc::OutputSurfaceClient* client_ = nullptr;
+
   display_compositor::GLHelper gl_helper_;
   std::unique_ptr<display_compositor::BufferQueue> buffer_queue_;
   cc::SyntheticBeginFrameSource* const synthetic_begin_frame_source_;
 
   gfx::Size reshape_size_;
   gfx::Size swap_size_;
 
   base::WeakPtrFactory<DirectOutputSurfaceOzone> weak_ptr_factory_;
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_SURFACES_DIRECT_OUTPUT_SURFACE_OZONE_H_