Blink handle selection handle visibility

cc/trees/layer_tree_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1953 matching lines @@
   bool update_lcd_text = false;
   if (!UpdateDrawProperties(update_lcd_text))
     return NULL;
   FindTouchEventLayerFunctor func = {screen_space_point};
   FindClosestMatchingLayerState state;
   FindClosestMatchingLayer(screen_space_point, layer_list_[0], func, &state);
   return state.closest_match;
 }
 
 void LayerTreeImpl::RegisterSelection(const LayerSelection& selection) {
+  if (selection_ == selection)
+    return;
+
+  if (IsActiveTree())
+    layer_tree_host_impl_->HandleVisibilityChanged();

[danakj, 2016/10/20 22:40:26]

I think a nicer way to frame this is to have the bool on LayerTreeImpl.

Then LTHI can query the active LayerTreeImpl to see if handle visibility
changed, instead of this informing LTHI if its the active tree.

It would require a Reset function for LTHI to call when it reads it. Maybe
GetAndReset could be combined if u want.

If LayerTreeImpl has lots of damage-generating things we could generalize this
eventually to like "get damage for tree or something" but I don't see that yet.

[amaralp, 2016/10/21 03:47:19]

Done.

[amaralp, 2016/10/21 03:47:19]

Done.

+
   selection_ = selection;
 }
 
 static gfx::SelectionBound ComputeViewportSelectionBound(
     const LayerSelectionBound& layer_bound,
     LayerImpl* layer,
     float device_scale_factor) {
   gfx::SelectionBound viewport_bound;
   viewport_bound.set_type(layer_bound.type);
 
@@ skipping 89 matching lines @@
 
 void LayerTreeImpl::ResetAllChangeTracking() {
   layers_that_should_push_properties_.clear();
   // Iterate over all layers, including masks.
   for (auto& layer : *layers_)
     layer->ResetChangeTracking();
   property_trees_.ResetAllChangeTracking();
 }
 
 }  // namespace cc