Delete widget tree (FrameView::parent_)

third_party/WebKit/Source/core/html/HTMLFrameOwnerElement.cpp

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 58 matching lines @@
 }
 
 static unsigned g_update_suspend_count = 0;
 
 HTMLFrameOwnerElement::UpdateSuspendScope::UpdateSuspendScope() {
   ++g_update_suspend_count;
 }
 
 void HTMLFrameOwnerElement::UpdateSuspendScope::
     PerformDeferredWidgetTreeOperations() {
+  VLOG(1) << "Performing deferred operations NewParent.size="
+          << FrameOrPluginNewParentMap().size() << ", TempRemoval.size="
+          << FrameOrPluginsPendingTemporaryRemovalFromParent().size()
+          << ", Dispose.size=" << FrameOrPluginsPendingDispose().size();
   FrameOrPluginToParentMap map;
   FrameOrPluginNewParentMap().swap(map);
   for (const auto& entry : map) {
     FrameOrPlugin* child = entry.key;
     FrameView* current_parent = child->Parent();
     FrameView* new_parent = entry.value;
     if (new_parent != current_parent) {
       if (current_parent)
         current_parent->RemoveChild(child);
       if (new_parent) {
@@ skipping 21 matching lines @@
 
 HTMLFrameOwnerElement::UpdateSuspendScope::~UpdateSuspendScope() {
   DCHECK_GT(g_update_suspend_count, 0u);
   if (g_update_suspend_count == 1)
     PerformDeferredWidgetTreeOperations();
   --g_update_suspend_count;
 }
 
 // Unlike MoveFrameOrPluginToParentSoon, this will not call dispose.
 void TemporarilyRemoveFrameOrPluginFromParentSoon(FrameOrPlugin* child) {
+  // child->SetFrameOrPluginState(FrameOrPlugin::kDeferred);
   if (g_update_suspend_count) {
+    VLOG(1) << "Defered temp remove child=" << child;
+    if (VLOG_IS_ON(2))
+      base::debug::StackTrace(10).Print();
     FrameOrPluginsPendingTemporaryRemovalFromParent().insert(child);
   } else {
     if (child->Parent())
       child->Parent()->RemoveChild(child);
   }
 }
 
 void MoveFrameOrPluginToParentSoon(FrameOrPlugin* child, FrameView* parent) {
+  // child->SetFrameOrPluginState(FrameOrPlugin::kDeferred);
   if (!g_update_suspend_count) {
     if (parent) {
       DCHECK(child != parent && !child->Parent());
       child->SetParent(parent);
     } else if (child->Parent()) {
       child->Parent()->RemoveChild(child);
       child->Dispose();
     }
     return;
   }
+  VLOG(1) << "Deferred New Parent child=" << child << ", parent=" << parent;
+  if (VLOG_IS_ON(2))
+    base::debug::StackTrace(10).Print();
   FrameOrPluginNewParentMap().Set(child, parent);
 }
 
 HTMLFrameOwnerElement::HTMLFrameOwnerElement(const QualifiedName& tag_name,
                                              Document& document)
     : HTMLElement(tag_name, document),
       content_frame_(nullptr),
       widget_(nullptr),
       sandbox_flags_(kSandboxNone) {}
 
@@ skipping 120 matching lines @@
 
 Document* HTMLFrameOwnerElement::getSVGDocument(
     ExceptionState& exception_state) const {
   Document* doc = contentDocument();
   if (doc && doc->IsSVGDocument())
     return doc;
   return nullptr;
 }
 
 void HTMLFrameOwnerElement::SetWidget(FrameOrPlugin* frame_or_plugin) {
+  VLOG(1) << "SetWidget old=" << widget_ << ", new=" << frame_or_plugin
+          << ", old parent=" << (!widget_ ? -1 : widget_ && widget_->Parent())
+          << ", count=" << g_update_suspend_count;
   if (frame_or_plugin == widget_)
     return;
 
   Document* doc = contentDocument();
   if (doc && doc->GetFrame()) {
     bool will_be_display_none = !frame_or_plugin;
     if (IsDisplayNone() != will_be_display_none) {
       doc->WillChangeFrameOwnerProperties(
           MarginWidth(), MarginHeight(), ScrollingMode(), will_be_display_none);
     }
   }
 
   if (widget_) {
     if (widget_->Parent())
       MoveFrameOrPluginToParentSoon(widget_, nullptr);
   }
 
   widget_ = frame_or_plugin;
   FrameOwnerPropertiesChanged();
 
   LayoutPart* layout_part = ToLayoutPart(GetLayoutObject());
   LayoutPartItem layout_part_item = LayoutPartItem(layout_part);
-  if (layout_part_item.IsNull())
+  if (layout_part_item.IsNull()) {
+    VLOG(1) << "SetWidget new=" << frame_or_plugin << ", parent=0";
     return;
+  }
 
   if (widget_) {
     layout_part_item.UpdateOnWidgetChange();
 
     DCHECK_EQ(GetDocument().View(), layout_part_item.GetFrameView());
     DCHECK(layout_part_item.GetFrameView());
+    VLOG(1) << "SetWidget new=" << frame_or_plugin
+            << ",  parent=" << layout_part_item.GetFrameView();
     MoveFrameOrPluginToParentSoon(widget_, layout_part_item.GetFrameView());
   }
 
   if (AXObjectCache* cache = GetDocument().ExistingAXObjectCache())
     cache->ChildrenChanged(layout_part);
 }
 
 FrameOrPlugin* HTMLFrameOwnerElement::ReleaseWidget() {
   if (!widget_)
     return nullptr;
@@ skipping 46 matching lines @@
 }
 
 DEFINE_TRACE(HTMLFrameOwnerElement) {
   visitor->Trace(content_frame_);
   visitor->Trace(widget_);
   HTMLElement::Trace(visitor);
   FrameOwner::Trace(visitor);
 }
 
 }  // namespace blink