Blink handle selection handle visibility

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 89035df5acb5fefdcaf9ac8ef63e2b78e05c1aca..6bbbd270a8cd6f27c6f11fca29e80f2f636e3f2d 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -82,6 +82,7 @@ LayerTreeImpl::LayerTreeImpl(
       needs_full_tree_sync_(true),
       next_activation_forces_redraw_(false),
       has_ever_been_drawn_(false),
+      handle_visibility_changed_(false),
       have_scroll_event_handlers_(false),
       event_listener_properties_(),
       top_controls_shrink_blink_size_(false),
@@ -1971,9 +1972,19 @@ LayerImpl* LayerTreeImpl::FindLayerThatIsHitByPointInTouchHandlerRegion(
 }
 
 void LayerTreeImpl::RegisterSelection(const LayerSelection& selection) {
+  if (selection_ == selection)
+    return;
+
+  handle_visibility_changed_ = true;
   selection_ = selection;
 }
 
+bool LayerTreeImpl::GetAndResetHandleVisibilityChanged() {
+  bool curr_handle_visibility_changed = handle_visibility_changed_;
+  handle_visibility_changed_ = false;
+  return curr_handle_visibility_changed;
+}
+
 static gfx::SelectionBound ComputeViewportSelectionBound(
     const LayerSelectionBound& layer_bound,
     LayerImpl* layer,