Revert of Pinch/Zoom Infrastructure & Plumbing CL

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 81a899232ece5c836ca45619e8a3f2efe8a33c30..7c4479d3ba6a18607f95e495c62d1954785c9d86 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -34,7 +34,6 @@
 class DebugRectHistory;
 class FrameRateCounter;
 class HeadsUpDisplayLayerImpl;
-class LayerScrollOffsetDelegateProxy;
 class LayerTreeDebugState;
 class LayerTreeHostImpl;
 class LayerTreeImpl;
@@ -114,24 +113,18 @@
     hud_layer_ = layer_impl;
   }
 
-  LayerImpl* InnerViewportScrollLayer() const;
-  // This function may return NULL, it is the caller's responsibility to check.
-  LayerImpl* OuterViewportScrollLayer() const;
-  gfx::Vector2dF TotalScrollOffset() const;
-  gfx::Vector2dF TotalMaxScrollOffset() const;
-  gfx::Vector2dF TotalScrollDelta() const;
-
+  LayerImpl* RootScrollLayer() const;
   LayerImpl* RootContainerLayer() const;
   LayerImpl* CurrentlyScrollingLayer() const;
   void SetCurrentlyScrollingLayer(LayerImpl* layer);
   void ClearCurrentlyScrollingLayer();
-  float VerticalAdjust(const LayerImpl* layer) const;
-
+
+  void FindRootScrollLayer();
+  void UpdateMaxScrollOffset();
   void SetViewportLayersFromIds(int page_scale_layer_id,
                                 int inner_viewport_scroll_layer_id,
                                 int outer_viewport_scroll_layer_id);
   void ClearViewportLayers();
-  LayerImpl* page_scale_layer() { return page_scale_layer_; }
   void ApplySentScrollAndScaleDeltasFromAbortedCommit();
   void ApplyScrollDeltasSinceBeginMainFrame();
 
@@ -214,8 +207,6 @@
 
   void SetRootLayerScrollOffsetDelegate(
       LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate);
-  void UpdateScrollOffsetDelegate();
-  gfx::Vector2dF GetDelegatedScrollOffset(LayerImpl* layer);
 
   // Call this function when you expect there to be a swap buffer.
   // See swap_promise.h for how to use SwapPromise.
@@ -240,18 +231,17 @@
  protected:
   explicit LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl);
 
+  void UpdateSolidColorScrollbars();
+
   void UpdateRootScrollLayerSizeDelta();
 
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
   scoped_ptr<LayerImpl> root_layer_;
   HeadsUpDisplayLayerImpl* hud_layer_;
+  LayerImpl* root_scroll_layer_;
   LayerImpl* currently_scrolling_layer_;
   LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate_;
-  scoped_ptr<LayerScrollOffsetDelegateProxy>
-      inner_viewport_scroll_delegate_proxy_;
-  scoped_ptr<LayerScrollOffsetDelegateProxy>
-      outer_viewport_scroll_delegate_proxy_;
   SkColor background_color_;
   bool has_transparent_background_;