Use IDCompositionSurface to implement DirectCompositionSurfaceWin.

cc/test/fake_output_surface.h

Index: cc/test/fake_output_surface.h
diff --git a/cc/test/fake_output_surface.h b/cc/test/fake_output_surface.h
index 4a83f8d9c7793339f8c7033c6c2d76be32022b4a..57d6aaedf8e0e9d54fdf9d74a39e3a1bfcc14040 100644
--- a/cc/test/fake_output_surface.h
+++ b/cc/test/fake_output_surface.h
@@ -62,6 +62,7 @@ class FakeOutputSurface : public OutputSurface {
   void EnsureBackbuffer() override {}
   void DiscardBackbuffer() override {}
   void BindFramebuffer() override;
+  void SetDrawRectangle(const gfx::Rect& rect) override;
   void Reshape(const gfx::Size& size,
                float device_scale_factor,
                const gfx::ColorSpace& color_space,
@@ -101,6 +102,9 @@ class FakeOutputSurface : public OutputSurface {
   const gfx::ColorSpace& last_reshape_color_space() {
     return last_reshape_color_space_;
   }
+  const gfx::Rect& last_set_draw_rectangle() {

[danakj, 2017/02/23 23:38:51]

nit: white space after function body

+    return last_set_draw_rectangle_;
+  }
 
  protected:
   explicit FakeOutputSurface(scoped_refptr<ContextProvider> context_provider);
@@ -118,6 +122,7 @@ class FakeOutputSurface : public OutputSurface {
   bool last_swap_rect_valid_ = false;
   gfx::Rect last_swap_rect_;
   gfx::ColorSpace last_reshape_color_space_;
+  gfx::Rect last_set_draw_rectangle_;
 
  private:
   void SwapBuffersAck();