cc: Remove dangerous LayerImpl::removeFromParent

cc/layer_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/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/stringprintf.h"
 #include "base/values.h"
 #include "cc/debug_border_draw_quad.h"
@@ skipping 54 matching lines @@
 }
 
 void LayerImpl::addChild(scoped_ptr<LayerImpl> child)
 {
     child->setParent(this);
     DCHECK_EQ(layerTreeHostImpl(), child->layerTreeHostImpl());
     m_children.append(child.Pass());
     m_layerTreeHostImpl->setNeedsUpdateDrawProperties();
 }
 
-void LayerImpl::removeFromParent()
+scoped_ptr<LayerImpl> LayerImpl::removeChild(LayerImpl* child)
 {
-    if (!m_parent)
-        return;
-
-    LayerImpl* parent = m_parent;
-    m_parent = 0;
-
-    for (size_t i = 0; i < parent->m_children.size(); ++i) {
-        if (parent->m_children[i] == this) {
+    for (size_t i = 0; i < m_children.size(); ++i) {
+        if (m_children[i] == child) {
+            scoped_ptr<LayerImpl> ret = m_children.take(i);
+            m_children.remove(i);
             m_layerTreeHostImpl->setNeedsUpdateDrawProperties();
-            // This remove call deletes |this|, so don't touch it anymore.
-            parent->m_children.remove(i);
-            return;
+            return ret.Pass();

[danakj, 2012/12/09 23:35:51]

nom nom, yay.

         }
     }
+    return scoped_ptr<LayerImpl>();
 }
 
 void LayerImpl::removeAllChildren()
 {
-    while (m_children.size())
-        m_children[0]->removeFromParent();
+    m_children.clear();
+    m_layerTreeHostImpl->setNeedsUpdateDrawProperties();
 }
 
 void LayerImpl::clearChildList()
 {
     if (m_children.isEmpty())
         return;
 
     m_children.clear();
     m_layerTreeHostImpl->setNeedsUpdateDrawProperties();
 }
@@ skipping 673 matching lines @@
 
 void LayerImpl::setVerticalScrollbarLayer(ScrollbarLayerImpl* scrollbarLayer)
 {
     if (!m_scrollbarAnimationController)
         m_scrollbarAnimationController = ScrollbarAnimationController::create(this);
     m_scrollbarAnimationController->setVerticalScrollbarLayer(scrollbarLayer);
     m_scrollbarAnimationController->updateScrollOffset(this);
 }
 
 }  // namespace cc