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

cc/test/pixel_test_output_surface.cc

Index: cc/test/pixel_test_output_surface.cc
diff --git a/cc/test/pixel_test_output_surface.cc b/cc/test/pixel_test_output_surface.cc
index e3f62bd576d047a82b55fbf3e0de291149cd2c33..c773a5227211a3b56ea4a0274481915219429566 100644
--- a/cc/test/pixel_test_output_surface.cc
+++ b/cc/test/pixel_test_output_surface.cc
@@ -17,7 +17,8 @@ PixelTestOutputSurface::PixelTestOutputSurface(
     scoped_ptr<SoftwareOutputDevice> software_device)
     : OutputSurface(software_device.Pass()), external_stencil_test_(false) {}
 
-void PixelTestOutputSurface::Reshape(gfx::Size size, float scale_factor) {
+void PixelTestOutputSurface::Reshape(const gfx::Size& size,
+                                     float scale_factor) {
   gfx::Size expanded_size(size.width() + surface_expansion_size_.width(),
                           size.height() + surface_expansion_size_.height());
   OutputSurface::Reshape(expanded_size, scale_factor);