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// Copyright 2014 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 "core/dom/ChildFrameDisconnector.h"
#include "core/dom/shadow/ElementShadow.h"
#include "core/dom/shadow/ShadowRoot.h"
#include "core/html/HTMLFrameOwnerElement.h"
#include "wtf/Assertions.h"
namespace blink {
#if DCHECK_IS_ON()
static unsigned checkConnectedSubframeCountIsConsistent(Node&);
#endif
void ChildFrameDisconnector::disconnect(DisconnectPolicy policy) {
#if DCHECK_IS_ON()
checkConnectedSubframeCountIsConsistent(root());
#endif
if (!root().connectedSubframeCount())
return;
if (policy == RootAndDescendants) {
collectFrameOwners(root());
} else {
for (Node* child = root().firstChild(); child; child = child->nextSibling())
collectFrameOwners(*child);
}
disconnectCollectedFrameOwners();
}
void ChildFrameDisconnector::collectFrameOwners(Node& root) {
if (!root.connectedSubframeCount())
return;
if (root.isHTMLElement() && root.isFrameOwnerElement())
m_frameOwners.push_back(&toHTMLFrameOwnerElement(root));
for (Node* child = root.firstChild(); child; child = child->nextSibling())
collectFrameOwners(*child);
ElementShadow* shadow = root.isElementNode() ? toElement(root).shadow() : 0;
if (shadow)
collectFrameOwners(*shadow);
}
void ChildFrameDisconnector::disconnectCollectedFrameOwners() {
// Must disable frame loading in the subtree so an unload handler cannot
// insert more frames and create loaded frames in detached subtrees.
SubframeLoadingDisabler disabler(root());
for (unsigned i = 0; i < m_frameOwners.size(); ++i) {
HTMLFrameOwnerElement* owner = m_frameOwners[i].get();
// Don't need to traverse up the tree for the first owner since no
// script could have moved it.
if (!i || root().isShadowIncludingInclusiveAncestorOf(owner))
owner->disconnectContentFrame();
}
}
void ChildFrameDisconnector::collectFrameOwners(ElementShadow& shadow) {
for (ShadowRoot* root = &shadow.youngestShadowRoot(); root;
root = root->olderShadowRoot())
collectFrameOwners(*root);
}
#if DCHECK_IS_ON()
static unsigned checkConnectedSubframeCountIsConsistent(Node& node) {
unsigned count = 0;
if (node.isElementNode()) {
if (node.isFrameOwnerElement() &&
toHTMLFrameOwnerElement(node).contentFrame())
count++;
if (ElementShadow* shadow = toElement(node).shadow()) {
for (ShadowRoot* root = &shadow->youngestShadowRoot(); root;
root = root->olderShadowRoot())
count += checkConnectedSubframeCountIsConsistent(*root);
}
}
for (Node* child = node.firstChild(); child; child = child->nextSibling())
count += checkConnectedSubframeCountIsConsistent(*child);
// If we undercount there's possibly a security bug since we'd leave frames
// in subtrees outside the document.
DCHECK_GE(node.connectedSubframeCount(), count);
// If we overcount it's safe, but not optimal because it means we'll traverse
// through the document in ChildFrameDisconnector looking for frames that have
// already been disconnected.
DCHECK_EQ(node.connectedSubframeCount(), count);
return count;
}
#endif
} // namespace blink
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