Standardize usage of virtual/override/final in content/browser/

content/browser/compositor/gpu_browser_compositor_output_surface.h

Index: content/browser/compositor/gpu_browser_compositor_output_surface.h
diff --git a/content/browser/compositor/gpu_browser_compositor_output_surface.h b/content/browser/compositor/gpu_browser_compositor_output_surface.h
index 0878d779cb427d21b861930d8fc06af3d3ac65d1..c558b56c04b022167857b411d9700bd5173fcd77 100644
--- a/content/browser/compositor/gpu_browser_compositor_output_surface.h
+++ b/content/browser/compositor/gpu_browser_compositor_output_surface.h
@@ -32,15 +32,15 @@ class GpuBrowserCompositorOutputSurface
       const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
       scoped_ptr<cc::OverlayCandidateValidator> overlay_candidate_validator);
 
-  virtual ~GpuBrowserCompositorOutputSurface();
+  ~GpuBrowserCompositorOutputSurface() override;
 
  protected:
   // cc::OutputSurface implementation.
-  virtual void SwapBuffers(cc::CompositorFrame* frame) override;
-  virtual bool BindToClient(cc::OutputSurfaceClient* client) override;
+  void SwapBuffers(cc::CompositorFrame* frame) override;
+  bool BindToClient(cc::OutputSurfaceClient* client) override;
 
 #if defined(OS_MACOSX)
-  virtual void OnSurfaceDisplayed() override;
+  void OnSurfaceDisplayed() override;
 #endif
 
   CommandBufferProxyImpl* GetCommandBufferProxy();