[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

cc/layers/nine_patch_layer_impl_unittest.cc

Index: cc/layers/nine_patch_layer_impl_unittest.cc
diff --git a/cc/layers/nine_patch_layer_impl_unittest.cc b/cc/layers/nine_patch_layer_impl_unittest.cc
index 60201110a25f9f207eb914db744c7740043fc64e..22f2c9496e395a39aa724f8cbe920e8d825ece3e 100644
--- a/cc/layers/nine_patch_layer_impl_unittest.cc
+++ b/cc/layers/nine_patch_layer_impl_unittest.cc
@@ -23,7 +23,7 @@
 namespace cc {
 namespace {
 
-gfx::Rect ToRoundedIntRect(gfx::RectF rect_f) {
+gfx::Rect ToRoundedIntRect(const gfx::RectF& rect_f) {
   return gfx::Rect(gfx::ToRoundedInt(rect_f.x()),
                    gfx::ToRoundedInt(rect_f.y()),
                    gfx::ToRoundedInt(rect_f.width()),
@@ -31,9 +31,9 @@ gfx::Rect ToRoundedIntRect(gfx::RectF rect_f) {
 }
 
 void NinePatchLayerLayoutTest(gfx::Size bitmap_size,
-                              gfx::Rect aperture_rect,
+                              const gfx::Rect& aperture_rect,
                               gfx::Size layer_size,
-                              gfx::Rect border,
+                              const gfx::Rect& border,
                               bool fill_center,
                               size_t expected_quad_size) {
   MockQuadCuller quad_culler;