[#5] Pass gfx structs by const ref (gfx::Vector2dF)

cc/layers/layer_impl.h

 // 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.
 
 #ifndef CC_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <set>
 #include <string>
 
@@ skipping 65 matching lines @@
 
   int id() const { return layer_id_; }
 
   // LayerAnimationValueProvider implementation.
   virtual gfx::Vector2dF ScrollOffsetForAnimation() const OVERRIDE;
 
   // LayerAnimationValueObserver implementation.
   virtual void OnFilterAnimated(const FilterOperations& filters) OVERRIDE;
   virtual void OnOpacityAnimated(float opacity) OVERRIDE;
   virtual void OnTransformAnimated(const gfx::Transform& transform) OVERRIDE;
-  virtual void OnScrollOffsetAnimated(gfx::Vector2dF scroll_offset) OVERRIDE;
+  virtual void OnScrollOffsetAnimated(
+      const gfx::Vector2dF& scroll_offset) OVERRIDE;
   virtual void OnAnimationWaitingForDeletion() OVERRIDE;
   virtual bool IsActive() const OVERRIDE;
 
   // Tree structure.
   LayerImpl* parent() { return parent_; }
   const LayerImpl* parent() const { return parent_; }
   const OwnedLayerImplList& children() const { return children_; }
   OwnedLayerImplList& children() { return children_; }
   LayerImpl* child_at(size_t index) const { return children_[index]; }
   void AddChild(scoped_ptr<LayerImpl> child);
@@ skipping 140 matching lines @@
   gfx::PointF position() const { return position_; }
 
   void SetIsContainerForFixedPositionLayers(bool container) {
     is_container_for_fixed_position_layers_ = container;
   }
   // This is a non-trivial function in Layer.
   bool IsContainerForFixedPositionLayers() const {
     return is_container_for_fixed_position_layers_;
   }
 
-  void SetFixedContainerSizeDelta(gfx::Vector2dF delta) {
+  void SetFixedContainerSizeDelta(const gfx::Vector2dF& delta) {
     fixed_container_size_delta_ = delta;
   }
   gfx::Vector2dF fixed_container_size_delta() const {
     return fixed_container_size_delta_;
   }
 
   void SetPositionConstraint(const LayerPositionConstraint& constraint) {
     position_constraint_ = constraint;
   }
   const LayerPositionConstraint& position_constraint() const {
@@ skipping 104 matching lines @@
                                       float* contents_scale_x,
                                       float* contents_scale_y,
                                       gfx::Size* content_bounds);
 
   void SetScrollOffsetDelegate(
       LayerScrollOffsetDelegate* scroll_offset_delegate);
   bool IsExternalFlingActive() const;
 
   void SetScrollOffset(gfx::Vector2d scroll_offset);
   void SetScrollOffsetAndDelta(gfx::Vector2d scroll_offset,
-                               gfx::Vector2dF scroll_delta);
+                               const gfx::Vector2dF& scroll_delta);
   gfx::Vector2d scroll_offset() const { return scroll_offset_; }
 
   void SetMaxScrollOffset(gfx::Vector2d max_scroll_offset);
   gfx::Vector2d max_scroll_offset() const { return max_scroll_offset_; }
 
-  void SetScrollDelta(gfx::Vector2dF scroll_delta);
+  void SetScrollDelta(const gfx::Vector2dF& scroll_delta);
   gfx::Vector2dF ScrollDelta() const;
 
   gfx::Vector2dF TotalScrollOffset() const;
 
   void SetSentScrollDelta(gfx::Vector2d sent_scroll_delta);
   gfx::Vector2d sent_scroll_delta() const { return sent_scroll_delta_; }
 
   // Returns the delta of the scroll that was outside of the bounds of the
   // initial scroll
-  gfx::Vector2dF ScrollBy(gfx::Vector2dF scroll);
+  gfx::Vector2dF ScrollBy(const gfx::Vector2dF& scroll);
 
   void SetScrollable(bool scrollable) { scrollable_ = scrollable; }
   bool scrollable() const { return scrollable_; }
 
   void set_user_scrollable_horizontal(bool scrollable) {
     user_scrollable_horizontal_ = scrollable;
   }
   void set_user_scrollable_vertical(bool scrollable) {
     user_scrollable_vertical_ = scrollable;
   }
@@ skipping 268 matching lines @@
   DrawProperties<LayerImpl> draw_properties_;
 
   scoped_refptr<base::debug::ConvertableToTraceFormat> debug_info_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_