Revert of Pinch/Zoom Infrastructure & Plumbing CL

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index ec2977b2557f02732117941c4d16e2679fcbd8d9..66fa84b4e24de51176166520fb8239f6b445c362 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -367,10 +367,8 @@
                                const gfx::Vector2dF& scroll_delta);
   gfx::Vector2d scroll_offset() const { return scroll_offset_; }
 
-  gfx::Vector2d MaxScrollOffset() const;
-  gfx::Vector2dF ClampScrollToMaxScrollOffset();
-  void SetScrollbarPosition(ScrollbarLayerImplBase* scrollbar_layer,
-                            LayerImpl* scrollbar_clip_layer) const;
+  void SetMaxScrollOffset(gfx::Vector2d max_scroll_offset);
+  gfx::Vector2d max_scroll_offset() const { return max_scroll_offset_; }
 
   void SetScrollDelta(const gfx::Vector2dF& scroll_delta);
   gfx::Vector2dF ScrollDelta() const;
@@ -384,8 +382,8 @@
   // initial scroll
   gfx::Vector2dF ScrollBy(const gfx::Vector2dF& scroll);
 
-  void SetScrollClipLayer(int scroll_clip_layer_id);
-  bool scrollable() const { return !!scroll_clip_layer_; }
+  void SetScrollable(bool scrollable) { scrollable_ = scrollable; }
+  bool scrollable() const { return scrollable_; }
 
   void set_user_scrollable_horizontal(bool scrollable) {
     user_scrollable_horizontal_ = scrollable;
@@ -479,15 +477,14 @@
     return scrollbar_animation_controller_.get();
   }
 
-  typedef std::set<ScrollbarLayerImplBase*> ScrollbarSet;
-  ScrollbarSet* scrollbars() { return scrollbars_.get(); }
-  void ClearScrollbars();
-  void AddScrollbar(ScrollbarLayerImplBase* layer);
-  void RemoveScrollbar(ScrollbarLayerImplBase* layer);
-  bool HasScrollbar(ScrollbarOrientation orientation) const;
-  void ScrollbarParametersDidChange();
-  int clip_height() {
-    return scroll_clip_layer_ ? scroll_clip_layer_->bounds().height() : 0;
+  void SetHorizontalScrollbarLayer(ScrollbarLayerImplBase* scrollbar_layer);
+  ScrollbarLayerImplBase* horizontal_scrollbar_layer() {
+    return horizontal_scrollbar_layer_;
+  }
+
+  void SetVerticalScrollbarLayer(ScrollbarLayerImplBase* scrollbar_layer);
+  ScrollbarLayerImplBase* vertical_scrollbar_layer() {
+    return vertical_scrollbar_layer_;
   }
 
   gfx::Rect LayerRectToContentRect(const gfx::RectF& layer_rect) const;
@@ -545,6 +542,8 @@
  private:
   void NoteLayerPropertyChangedForDescendantsInternal();
 
+  void UpdateScrollbarPositions();
+
   virtual const char* LayerTypeAsString() const;
 
   // Properties internal to LayerImpl
@@ -577,7 +576,6 @@
   gfx::Size bounds_;
   gfx::Vector2d scroll_offset_;
   LayerScrollOffsetDelegate* scroll_offset_delegate_;
-  LayerImpl* scroll_clip_layer_;
   bool scrollable_ : 1;
   bool should_scroll_on_main_thread_ : 1;
   bool have_wheel_event_handlers_ : 1;
@@ -620,6 +618,7 @@
 
   gfx::Vector2dF scroll_delta_;
   gfx::Vector2d sent_scroll_delta_;
+  gfx::Vector2d max_scroll_offset_;
   gfx::Vector2dF last_scroll_offset_;
 
   // The global depth value of the center of the layer. This value is used
@@ -655,7 +654,10 @@
   // Manages scrollbars for this layer
   scoped_ptr<ScrollbarAnimationController> scrollbar_animation_controller_;
 
-  scoped_ptr<ScrollbarSet> scrollbars_;
+  // Weak pointers to this layer's scrollbars, if it has them. Updated during
+  // tree synchronization.
+  ScrollbarLayerImplBase* horizontal_scrollbar_layer_;
+  ScrollbarLayerImplBase* vertical_scrollbar_layer_;
 
   ScopedPtrVector<CopyOutputRequest> copy_requests_;