Note scrollbar layer properties changed when position changes.

cc/layers/scrollbar_layer_impl.h

 // Copyright 2012 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_SCROLLBAR_LAYER_IMPL_H_
 #define CC_LAYERS_SCROLLBAR_LAYER_IMPL_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/input/scrollbar.h"
 #include "cc/layers/layer_impl.h"
@@ skipping 24 matching lines @@
 
   virtual void DidLoseOutputSurface() OVERRIDE;
 
   int scroll_layer_id() const { return scroll_layer_id_; }
   void set_scroll_layer_id(int id) { scroll_layer_id_ = id; }
 
   ScrollbarOrientation Orientation() const;
   float CurrentPos() const;
   int Maximum() const;
 
-  void set_thumb_thickness(int thumb_thickness) {
-    thumb_thickness_ = thumb_thickness;
-  }
+  void SetThumbThickness(int thumb_thickness);
   int thumb_thickness() const { return thumb_thickness_; }
-  void set_thumb_length(int thumb_length) {
-    thumb_length_ = thumb_length;
-  }
-  void set_track_start(int track_start) {
-    track_start_ = track_start;
-  }
-  void set_track_length(int track_length) {
-    track_length_ = track_length;
-  }
-  void set_vertical_adjust(float vertical_adjust) {
-    vertical_adjust_ = vertical_adjust;
-  }
+  void SetThumbLength(int thumb_length);
+  void SetTrackStart(int track_start);
+  void SetTrackLength(int track_length);
+  void SetVerticalAdjust(float vertical_adjust);
   void set_track_resource_id(ResourceProvider::ResourceId id) {
     track_resource_id_ = id;
   }
   void set_thumb_resource_id(ResourceProvider::ResourceId id) {
     thumb_resource_id_ = id;
   }
-  void set_visible_to_total_length_ratio(float ratio) {
-    visible_to_total_length_ratio_ = ratio;
-  }
+  void SetVisibleToTotalLengthRatio(float ratio);
   void set_is_overlay_scrollbar(bool is_overlay_scrollbar) {
     is_overlay_scrollbar_ = is_overlay_scrollbar;
   }
   bool is_overlay_scrollbar() const { return is_overlay_scrollbar_; }
 
   void SetCurrentPos(float current_pos);
   void SetMaximum(int maximum);
 
   gfx::Rect ComputeThumbQuadRect() const;
 
@@ skipping 26 matching lines @@
 
   int scroll_layer_id_;
 
   bool is_overlay_scrollbar_;
 
   DISALLOW_COPY_AND_ASSIGN(ScrollbarLayerImpl);
 };
 
 }  // namespace cc
 #endif  // CC_LAYERS_SCROLLBAR_LAYER_IMPL_H_