Add FBO support in Android WebView

ui/gl/gl_surface_stub.h

Index: ui/gl/gl_surface_stub.h
diff --git a/ui/gl/gl_surface_stub.h b/ui/gl/gl_surface_stub.h
index 14e24b07e625f3c04788e25e3f83750b6b15b341..6495b52e6373d949ec7ebc6a832fc5aec4a1193d 100644
--- a/ui/gl/gl_surface_stub.h
+++ b/ui/gl/gl_surface_stub.h
@@ -12,11 +12,15 @@ namespace gfx {
 // A GLSurface that does nothing for unit tests.
 class GL_EXPORT GLSurfaceStub : public GLSurface {
  public:
+  GLSurfaceStub();
+
   void SetSize(const gfx::Size& size) { size_ = size; }
+  void SaveCurrentFBO();
 
   // Implement GLSurface.
   virtual void Destroy() OVERRIDE;
   virtual bool IsOffscreen() OVERRIDE;
+  virtual unsigned int GetBackingFrameBufferObject();
   virtual bool SwapBuffers() OVERRIDE;
   virtual gfx::Size GetSize() OVERRIDE;
   virtual void* GetHandle() OVERRIDE;
@@ -25,6 +29,7 @@ class GL_EXPORT GLSurfaceStub : public GLSurface {
   virtual ~GLSurfaceStub();
 
  private:
+  unsigned int fbo_;
   gfx::Size size_;
 };