Add OVERRIDE to gpu/ and gl/.

ui/gfx/gl/gl_surface_cgl.h

Index: ui/gfx/gl/gl_surface_cgl.h
diff --git a/ui/gfx/gl/gl_surface_cgl.h b/ui/gfx/gl/gl_surface_cgl.h
index 98775c6886841eb7467990dd87ac674c9f834c91..6924c69c6cc20a78cafed75b4efdf104fcd9d7d4 100644
--- a/ui/gfx/gl/gl_surface_cgl.h
+++ b/ui/gfx/gl/gl_surface_cgl.h
@@ -30,12 +30,12 @@ class PbufferGLSurfaceCGL : public GLSurfaceCGL {
   virtual ~PbufferGLSurfaceCGL();
 
   // Implement GLSurface.
-  virtual bool Initialize();
-  virtual void Destroy();
-  virtual bool IsOffscreen();
-  virtual bool SwapBuffers();
-  virtual gfx::Size GetSize();
-  virtual void* GetHandle();
+  virtual bool Initialize() OVERRIDE;
+  virtual void Destroy() OVERRIDE;
+  virtual bool IsOffscreen() OVERRIDE;
+  virtual bool SwapBuffers() OVERRIDE;
+  virtual gfx::Size GetSize() OVERRIDE;
+  virtual void* GetHandle() OVERRIDE;
 
  private:
   gfx::Size size_;