Pinch/Zoom Infrastructure & Plumbing CL

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 6d9619f8a67a67f4a0747d3287ffff3c41e3d122..bcfb79d75959d374882c0f3b9abee671bb1fdc46 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -269,11 +269,10 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   gfx::Vector2d scroll_offset() const { return scroll_offset_; }
   void SetScrollOffsetFromImplSide(gfx::Vector2d scroll_offset);
 
-  void SetMaxScrollOffset(gfx::Vector2d max_scroll_offset);
-  gfx::Vector2d max_scroll_offset() const { return max_scroll_offset_; }
+  gfx::Vector2d MaxScrollOffset() const;
 
-  void SetScrollable(bool scrollable);
-  bool scrollable() const { return scrollable_; }
+  void SetScrollClipLayer(Layer* clip_layer);
+  bool scrollable() const { return scroll_clip_layer_; }
 
   void SetUserScrollable(bool horizontal, bool vertical);
   bool user_scrollable_horizontal() const {
@@ -568,7 +567,9 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   gfx::Size bounds_;
 
   gfx::Vector2d scroll_offset_;
-  gfx::Vector2d max_scroll_offset_;
+  // This variable indicates which ancestor layer (if any) defines the maximum

[enne (OOO), 2014/01/21 19:00:06]

Defines is is not quite right.  It's really the relationship between this
(scroll) layer and its clip layer, right?

[wjmaclean, 2014/01/21 22:37:27]

Done.

+  // scroll offset for this layer.
+  Layer* scroll_clip_layer_;
   bool scrollable_ : 1;
   bool should_scroll_on_main_thread_ : 1;
   bool have_wheel_event_handlers_ : 1;