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

cc/output/output_surface.h

 // Copyright 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 CC_OUTPUT_OUTPUT_SURFACE_H_
 #define CC_OUTPUT_OUTPUT_SURFACE_H_
 
 #include <deque>
 #include <memory>
 
@@ skipping 45 matching lines @@
   // Constructor for GL-based compositing.
   explicit OutputSurface(scoped_refptr<ContextProvider> context_provider);
   // Constructor for software compositing.
   explicit OutputSurface(std::unique_ptr<SoftwareOutputDevice> software_device);
   // Constructor for Vulkan-based compositing.
   explicit OutputSurface(
       scoped_refptr<VulkanContextProvider> vulkan_context_provider);
 
   virtual ~OutputSurface();
 
-  // Called by the Display to initialize the OutputSurface. This also specifies
-  // the thread that the OutputSurface will be used on as tests create and then
-  // bind the class on different threads.
-  virtual bool BindToClient(OutputSurfaceClient* client);
-
   const Capabilities& capabilities() const { return capabilities_; }
 
   // Obtain the 3d context or the software device associated with this output
   // surface. Either of these may return a null pointer, but not both.
   // In the event of a lost context, the entire output surface should be
   // recreated.
   ContextProvider* context_provider() const { return context_provider_.get(); }
   VulkanContextProvider* vulkan_context_provider() const {
     return vulkan_context_provider_.get();
   }
   SoftwareOutputDevice* software_device() const {
     return software_device_.get();
   }
 
+  virtual void BindToClient(OutputSurfaceClient* client) = 0;
+
   virtual void EnsureBackbuffer() = 0;
   virtual void DiscardBackbuffer() = 0;
 
   // Bind the default framebuffer for drawing to, only valid for GL backed
   // OutputSurfaces.
   virtual void BindFramebuffer() = 0;
 
   // Get the class capable of informing cc of hardware overlay capability.
   virtual OverlayCandidateValidator* GetOverlayCandidateValidator() const = 0;
 
@@ skipping 17 matching lines @@
   // Gives the GL internal format that should be used for calling CopyTexImage2D
   // when the framebuffer is bound via BindFramebuffer().
   virtual uint32_t GetFramebufferCopyTextureFormat() = 0;
 
   // Swaps the current backbuffer to the screen. For successful swaps, the
   // implementation must call OutputSurfaceClient::DidReceiveSwapBuffersAck()
   // after returning from this method in order to unblock the next frame.
   virtual void SwapBuffers(OutputSurfaceFrame frame) = 0;
 
  protected:
-  // Used internally for the context provider to inform the client about loss,
-  // and can be overridden to change behaviour instead of informing the client.
-  virtual void DidLoseOutputSurface();
-
-  OutputSurfaceClient* client_ = nullptr;
-
   struct OutputSurface::Capabilities capabilities_;
   scoped_refptr<ContextProvider> context_provider_;
   scoped_refptr<VulkanContextProvider> vulkan_context_provider_;
   std::unique_ptr<SoftwareOutputDevice> software_device_;
-  base::ThreadChecker thread_checker_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(OutputSurface);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OUTPUT_SURFACE_H_