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

cc/quads/io_surface_draw_quad.h

Index: cc/quads/io_surface_draw_quad.h
diff --git a/cc/quads/io_surface_draw_quad.h b/cc/quads/io_surface_draw_quad.h
index 9a9fa09bb3d3c8e1db9a0a0e8dd99909b81222e7..39975c82a54f1dcb4c4cdfaecfcc85b2045e3fe8 100644
--- a/cc/quads/io_surface_draw_quad.h
+++ b/cc/quads/io_surface_draw_quad.h
@@ -25,7 +25,7 @@ class CC_EXPORT IOSurfaceDrawQuad : public DrawQuad {
   void SetNew(const SharedQuadState* shared_quad_state,
               const gfx::Rect& rect,
               const gfx::Rect& opaque_rect,
-              gfx::Size io_surface_size,
+              const gfx::Size& io_surface_size,
               unsigned io_surface_resource_id,
               Orientation orientation);
 
@@ -34,7 +34,7 @@ class CC_EXPORT IOSurfaceDrawQuad : public DrawQuad {
               const gfx::Rect& opaque_rect,
               const gfx::Rect& visible_rect,
               bool needs_blending,
-              gfx::Size io_surface_size,
+              const gfx::Size& io_surface_size,
               unsigned io_surface_resource_id,
               Orientation orientation);