First Implementation of Snapped Points

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index f065db808f4ddc4a38c0574396da1168d9f52d59..2d6cc65e964ed63013f53bbd63a112e1d7aaebc6 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -175,6 +175,7 @@ class CC_EXPORT LayerTreeHostImpl
       base::TimeDelta delayed_by = base::TimeDelta()) override;
   void ApplyScroll(ScrollNode* scroll_node, ScrollState* scroll_state);
   InputHandlerScrollResult ScrollBy(ScrollState* scroll_state) override;
+  void SnapAfterGestureScroll(const gfx::Point&) override;
   void RequestUpdateForSynchronousInputHandler() override;
   void SetSynchronousInputHandlerRootScrollOffset(
       const gfx::ScrollOffset& root_offset) override;
@@ -664,6 +665,9 @@ class CC_EXPORT LayerTreeHostImpl
   bool IsInitialScrollHitTestReliable(LayerImpl* layer, const gfx::PointF&);
   void DistributeScrollDelta(ScrollState* scroll_state);
 
+  void FindSnappedOffset(gfx::Vector2dF* snapped_offset,
+                         const gfx::Vector2dF& original_offset) override;
+
   bool AnimatePageScale(base::TimeTicks monotonic_time);
   bool AnimateScrollbars(base::TimeTicks monotonic_time);
   bool AnimateBrowserControls(base::TimeTicks monotonic_time);