[#7] Resubmitted - Pass gfx structs by const ref (gfx::Size)

cc/output/direct_renderer.h

Index: cc/output/direct_renderer.h
diff --git a/cc/output/direct_renderer.h b/cc/output/direct_renderer.h
index 4a447aaf1f2af4e4827b8df1587c1c035ce0771c..08b75a13692e210f7d01950771ff290899ca6915 100644
--- a/cc/output/direct_renderer.h
+++ b/cc/output/direct_renderer.h
@@ -74,7 +74,7 @@ class CC_EXPORT DirectRenderer : public Renderer {
   void InitializeViewport(DrawingFrame* frame,
                           const gfx::Rect& draw_rect,
                           const gfx::Rect& viewport_rect,
-                          gfx::Size surface_size);
+                          const gfx::Size& surface_size);
   gfx::Rect MoveFromDrawToWindowSpace(const gfx::RectF& draw_rect) const;
 
   bool NeedDeviceClip(const DrawingFrame* frame) const;