Implement pinch-zoom scaling for main-frame scrollbars and pinch-zoom overlay scrollbars.

cc/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_SCROLLBAR_LAYER_IMPL_H_
 #define CC_SCROLLBAR_LAYER_IMPL_H_
 
 #include "cc/cc_export.h"
 #include "cc/scrollbar_geometry_fixed_thumb.h"
 #include "cc/scrollbar_layer_impl_base.h"
@@ skipping 13 matching lines @@
     int scrollLayerId() const { return m_scrollLayerId; }
     void setScrollLayerId(int id) { m_scrollLayerId = id; }
 
     void setScrollbarData(WebKit::WebScrollbar*);
     void setThumbSize(gfx::Size size);
 
     void setBackTrackResourceId(ResourceProvider::ResourceId id) { m_backTrackResourceId = id; }
     void setForeTrackResourceId(ResourceProvider::ResourceId id) { m_foreTrackResourceId = id; }
     void setThumbResourceId(ResourceProvider::ResourceId id) { m_thumbResourceId = id; }
 
+    void setIsPinchZoomScrollbar(bool isPinchZoomScrollbar) { m_isPinchZoomScrollbar = isPinchZoomScrollbar; }
+    bool isPinchZoomScrollbar() { return m_isPinchZoomScrollbar; }
 
     // ScrollbarLayerImplBase implementation.
     virtual float currentPos() const OVERRIDE;
     virtual int totalSize() const OVERRIDE;
     virtual int maximum() const OVERRIDE;
 
     void setCurrentPos(float currentPos) { m_currentPos = currentPos; }
     void setTotalSize(int totalSize) { m_totalSize = totalSize; }
     void setMaximum(int maximum) { m_maximum = maximum; }
 
@@ skipping 63 matching lines @@
     WebKit::WebScrollbar::Orientation m_orientation;
     WebKit::WebScrollbar::ScrollbarControlSize m_controlSize;
     WebKit::WebScrollbar::ScrollbarPart m_pressedPart;
     WebKit::WebScrollbar::ScrollbarPart m_hoveredPart;
 
     bool m_isScrollableAreaActive;
     bool m_isScrollViewScrollbar;
     bool m_enabled;
     bool m_isCustomScrollbar;
     bool m_isOverlayScrollbar;
+    bool m_isPinchZoomScrollbar;
 };
 
 }
 #endif  // CC_SCROLLBAR_LAYER_IMPL_H_