Fix RemoveFromScrollTree and RemoveFromClipTree

cc/layers/layer.cc

 // Copyright 2010 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/layers/layer.h"
 
 #include <algorithm>
 
 #include "base/atomic_sequence_num.h"
 #include "base/debug/trace_event.h"
@@ skipping 72 matching lines @@
   // Our parent should be holding a reference to us so there should be no
   // way for us to be destroyed while we still have a parent.
   DCHECK(!parent());
   // Similarly we shouldn't have a layer tree host since it also keeps a
   // reference to us.
   DCHECK(!layer_tree_host());
 
   layer_animation_controller_->RemoveValueObserver(this);
   layer_animation_controller_->remove_value_provider(this);
 
+  RemoveFromScrollTree();
+  RemoveFromClipTree();
+
   // Remove the parent reference from all children and dependents.
   RemoveAllChildren();
   if (mask_layer_.get()) {
     DCHECK_EQ(this, mask_layer_->parent());
     mask_layer_->RemoveFromParent();
   }
   if (replica_layer_.get()) {
     DCHECK_EQ(this, replica_layer_->parent());
     replica_layer_->RemoveFromParent();
   }
-
-  RemoveFromScrollTree();
-  RemoveFromClipTree();
 }
 
 void Layer::SetLayerTreeHost(LayerTreeHost* host) {
   if (layer_tree_host_ == host)
     return;
 
   layer_tree_host_ = host;
 
   // When changing hosts, the layer needs to commit its properties to the impl
   // side for the new host.
@@ skipping 1076 matching lines @@
 RenderingStatsInstrumentation* Layer::rendering_stats_instrumentation() const {
   return layer_tree_host_->rendering_stats_instrumentation();
 }
 
 bool Layer::SupportsLCDText() const {
   return false;
 }
 
 void Layer::RemoveFromScrollTree() {
   if (scroll_children_.get()) {
-    for (std::set<Layer*>::iterator it = scroll_children_->begin();
-        it != scroll_children_->end(); ++it)
-      (*it)->scroll_parent_ = NULL;
+    std::set<Layer*> copy = *scroll_children_;
+    for (std::set<Layer*>::iterator it = copy.begin(); it != copy.end(); ++it)
+      (*it)->SetScrollParent(NULL);
   }
 
-  if (scroll_parent_)
-    scroll_parent_->RemoveScrollChild(this);
-
-  scroll_parent_ = NULL;
+  DCHECK(!scroll_children_);
+  SetScrollParent(NULL);
 }
 
 void Layer::RemoveFromClipTree() {
   if (clip_children_.get()) {
-    for (std::set<Layer*>::iterator it = clip_children_->begin();
-        it != clip_children_->end(); ++it)
-      (*it)->clip_parent_ = NULL;
+    std::set<Layer*> copy = *clip_children_;
+    for (std::set<Layer*>::iterator it = copy.begin(); it != copy.end(); ++it)
+      (*it)->SetClipParent(NULL);
   }
 
-  if (clip_parent_)
-    clip_parent_->RemoveClipChild(this);
-
-  clip_parent_ = NULL;
+  DCHECK(!clip_children_);
+  SetClipParent(NULL);
 }
 
 void Layer::AddDrawableDescendants(int num) {
   DCHECK_GE(num_descendants_that_draw_content_, 0);
   DCHECK_GE(num_descendants_that_draw_content_ + num, 0);
   if (num == 0)
     return;
   num_descendants_that_draw_content_ += num;
   SetNeedsCommit();
   if (parent())
     parent()->AddDrawableDescendants(num);
 }
 
 void Layer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 bool Layer::HasDelegatedContent() const {
   return false;
 }
 
 }  // namespace cc