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

cc/layers/picture_layer_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/picture_layer.h"
 
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/picture_layer_impl.h"
 #include "cc/resources/resource_update_queue.h"
 #include "cc/test/fake_layer_tree_host.h"
 #include "cc/test/fake_picture_layer_impl.h"
 #include "cc/test/fake_proxy.h"
 #include "cc/test/impl_side_painting_settings.h"
 #include "cc/trees/occlusion_tracker.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
 namespace {
 
 class MockContentLayerClient : public ContentLayerClient {
  public:
   virtual void PaintContents(SkCanvas* canvas,
-                             gfx::Rect clip,
+                             const gfx::Rect& clip,
                              gfx::RectF* opaque) OVERRIDE {}
   virtual void DidChangeLayerCanUseLCDText() OVERRIDE {}
 };
 
 TEST(PictureLayerTest, NoTilesIfEmptyBounds) {
   MockContentLayerClient client;
   scoped_refptr<PictureLayer> layer = PictureLayer::Create(&client);
   layer->SetBounds(gfx::Size(10, 10));
 
   scoped_ptr<FakeLayerTreeHost> host = FakeLayerTreeHost::Create();
@@ skipping 26 matching lines @@
     EXPECT_TRUE(layer_impl->pile()->size() == gfx::Size(0, 0));
     EXPECT_TRUE(layer_impl->pile()->recorded_region().IsEmpty());
   }
 #ifndef NDEBUG
   proxy.SetCurrentThreadIsImplThread(false);
 #endif
 }
 
 }  // namespace
 }  // namespace cc