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

cc/layer_tree_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_LAYER_TREE_IMPL_H_
 #define CC_LAYER_TREE_IMPL_H_
 
 #include "cc/layer_impl.h"
 
 namespace cc {
 
 class DebugRectHistory;
 class FrameRateCounter;
 class HeadsUpDisplayLayerImpl;
 class LayerTreeDebugState;
 class LayerTreeHostImpl;
 class LayerTreeImpl;
 class LayerTreeSettings;
 class OutputSurface;
+class PinchZoomScrollbarsManager;
 class ResourceProvider;
 class TileManager;
 
 class CC_EXPORT LayerTreeImpl {
  public:
   static scoped_ptr<LayerTreeImpl> create(LayerTreeHostImpl* layer_tree_host_impl)
   {
     return make_scoped_ptr(new LayerTreeImpl(layer_tree_host_impl));
   }
   virtual ~LayerTreeImpl();
@@ skipping 25 matching lines @@
   LayerImpl* RootLayer() const { return root_layer_.get(); }
   void SetRootLayer(scoped_ptr<LayerImpl>);
   scoped_ptr<LayerImpl> DetachLayerTree();
 
   int source_frame_number() const { return source_frame_number_; }
   void set_source_frame_number(int frame_number) { source_frame_number_ = frame_number; }
 
   HeadsUpDisplayLayerImpl* hud_layer() { return hud_layer_; }
   void set_hud_layer(HeadsUpDisplayLayerImpl* layer_impl) { hud_layer_ = layer_impl; }
 
+  ScrollbarLayerImpl* pinch_zoom_scrollbar_vertical() { return pinch_zoom_scrollbar_vertical_; }
+  void set_pinch_zoom_scrollbar_vertical(ScrollbarLayerImpl* layer_impl);
+
+  ScrollbarLayerImpl* pinch_zoom_scrollbar_horizontal() { return pinch_zoom_scrollbar_horizontal_; }
+  void set_pinch_zoom_scrollbar_horizontal(ScrollbarLayerImpl* layer_impl);
+
+  PinchZoomScrollbarsManager* pinch_zoom_scrollbars_manager() { return pinch_zoom_scrollbars_.get(); }
+
   LayerImpl* root_scroll_layer() { return root_scroll_layer_; }
   void set_root_scroll_layer(LayerImpl* layer_impl) { root_scroll_layer_ = layer_impl; }
 
   LayerImpl* currently_scrolling_layer() { return currently_scrolling_layer_; }
   void set_currently_scrolling_layer(LayerImpl* layer_impl) { currently_scrolling_layer_ = layer_impl; }
 
   void ClearCurrentlyScrollingLayer();
 
 protected:
   LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl);
 
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
   scoped_ptr<LayerImpl> root_layer_;
   HeadsUpDisplayLayerImpl* hud_layer_;
+  ScrollbarLayerImpl* pinch_zoom_scrollbar_vertical_;
+  ScrollbarLayerImpl* pinch_zoom_scrollbar_horizontal_;
   LayerImpl* root_scroll_layer_;
   LayerImpl* currently_scrolling_layer_;
 
+  scoped_ptr<PinchZoomScrollbarsManager> pinch_zoom_scrollbars_;
+
   // Persisted state
   int scrolling_layer_id_from_previous_tree_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }
 
 #endif  // CC_LAYER_TREE_IMPL_H_