Implement native GMB backbuffers in the GLES2 Command Decoder.

cc/test/test_image_factory.h

Index: cc/test/test_image_factory.h
diff --git a/cc/test/test_image_factory.h b/cc/test/test_image_factory.h
index 42a92e37a1bd3d72d82d5225106c81a158cb8828..c5cce70f35ae4484d10f619b4203a0bdd52e3893 100644
--- a/cc/test/test_image_factory.h
+++ b/cc/test/test_image_factory.h
@@ -22,6 +22,10 @@ class TestImageFactory : public gpu::ImageFactory {
       gfx::BufferFormat format,
       unsigned internalformat,
       int client_id) override;
+  scoped_refptr<gl::GLImage> CreateAnonymousImage(
+      const gfx::Size& size,
+      gfx::BufferFormat format,
+      unsigned internalformat) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestImageFactory);