[#3] Pass gfx structs by const ref (gfx::SizeF)

cc/layers/layer_impl_unittest.cc

 // Copyright 2011 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/layer_impl.h"
 
 #include "cc/output/filter_operation.h"
 #include "cc/output/filter_operations.h"
 #include "cc/test/fake_impl_proxy.h"
 #include "cc/test/fake_layer_tree_host_impl.h"
@@ skipping 384 matching lines @@
   virtual gfx::Vector2dF GetTotalScrollOffset() OVERRIDE {
     return fixed_offset_;
   }
   virtual bool IsExternalFlingActive() const OVERRIDE { return false; }
 
   void set_fixed_offset(gfx::Vector2dF fixed_offset) {
     fixed_offset_ = fixed_offset;
   }
 
   virtual void SetTotalPageScaleFactor(float page_scale_factor) OVERRIDE {}
-  virtual void SetScrollableSize(gfx::SizeF scrollable_size) OVERRIDE {}
+  virtual void SetScrollableSize(const gfx::SizeF& scrollable_size) OVERRIDE {}
 
  private:
   gfx::Vector2dF fixed_offset_;
 };
 
 TEST_F(LayerImplScrollTest, ScrollByWithIgnoringDelegate) {
   gfx::Vector2d max_scroll_offset(50, 80);
   gfx::Vector2d scroll_offset(10, 5);
   layer()->SetMaxScrollOffset(max_scroll_offset);
   layer()->SetScrollOffset(scroll_offset);
@@ skipping 31 matching lines @@
  public:
   virtual void SetMaxScrollOffset(gfx::Vector2dF max_scroll_offset) OVERRIDE {}
   virtual void SetTotalScrollOffset(gfx::Vector2dF new_value) OVERRIDE {
     current_offset_ = new_value;
   }
   virtual gfx::Vector2dF GetTotalScrollOffset() OVERRIDE {
     return current_offset_;
   }
   virtual bool IsExternalFlingActive() const OVERRIDE { return false; }
   virtual void SetTotalPageScaleFactor(float page_scale_factor) OVERRIDE {}
-  virtual void SetScrollableSize(gfx::SizeF scrollable_size) OVERRIDE {}
+  virtual void SetScrollableSize(const gfx::SizeF& scrollable_size) OVERRIDE {}
 
  private:
   gfx::Vector2dF current_offset_;
 };
 
 TEST_F(LayerImplScrollTest, ScrollByWithAcceptingDelegate) {
   gfx::Vector2d max_scroll_offset(50, 80);
   gfx::Vector2d scroll_offset(10, 5);
   layer()->SetMaxScrollOffset(max_scroll_offset);
   layer()->SetScrollOffset(scroll_offset);
@@ skipping 109 matching lines @@
   layer()->SetMaxScrollOffset(max_scroll_offset);
   layer()->SetScrollOffset(scroll_offset);
   gfx::Vector2dF unscrolled = layer()->ScrollBy(scroll_delta);
 
   EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 8.5f), unscrolled);
   EXPECT_VECTOR_EQ(gfx::Vector2dF(30.5f, 5), layer()->TotalScrollOffset());
 }
 
 }  // namespace
 }  // namespace cc