Include scroll snap in scroll position used for sticky offset calculation.

cc/trees/property_tree.cc

Index: cc/trees/property_tree.cc
diff --git a/cc/trees/property_tree.cc b/cc/trees/property_tree.cc
index 500f6ec7580f58b2ffa128c55177bd000f9cc40d..19f131f899dbbf11f0e440c95348c923d079f1fa 100644
--- a/cc/trees/property_tree.cc
+++ b/cc/trees/property_tree.cc
@@ -424,9 +424,15 @@ gfx::Vector2dF StickyPositionOffset(TransformTree* tree, TransformNode* node) {
   gfx::ScrollOffset scroll_offset =
       tree->property_trees()->scroll_tree.current_scroll_offset(
           scroll_node->owner_id);
+  gfx::PointF scroll_position(scroll_offset.x(), scroll_offset.y());
+  // The scroll position does not include snapping which shifts the scroll
+  // offset to align to a pixel boundary, we need to manually include it here.
+  scroll_position -= tree->property_trees()
+                         ->transform_tree.Node(scroll_node->transform_id)
+                         ->scroll_snap;
 
   gfx::RectF clip(
-      gfx::PointF(scroll_offset.x(), scroll_offset.y()),
+      scroll_position,
       gfx::SizeF(tree->property_trees()->scroll_tree.scroll_clip_layer_bounds(
           scroll_node->id)));
   gfx::Vector2dF sticky_offset(