Track connected subframes per-Document instead of per-Node.

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 135 matching lines @@
     if (!layoutObject() || !layoutObject()->isLayoutPart())
         return nullptr;
     return toLayoutPart(layoutObject());
 }
 
 void HTMLFrameOwnerElement::setContentFrame(Frame& frame)
 {
     // Make sure we will not end up with two frames referencing the same owner element.
     ASSERT(!m_contentFrame || m_contentFrame->owner() != this);
     // Disconnected frames should not be allowed to load.
-    ASSERT(inDocument());
+    ASSERT(inActiveDocument());
+
     m_contentFrame = &frame;
-
-    for (ContainerNode* node = this; node; node = node->parentOrShadowHostNode())
-        node->incrementConnectedSubframeCount();
+    document().subframeTracker().connectSubframe(*this);
 }
 
 void HTMLFrameOwnerElement::clearContentFrame()
 {
     if (!m_contentFrame)
         return;
 
+    // If there's a connected content frame, the parent frame must be active.
+    ASSERT(inActiveDocument());
     m_contentFrame = nullptr;
-
-    for (ContainerNode* node = this; node; node = node->parentOrShadowHostNode())
-        node->decrementConnectedSubframeCount();
+    document().subframeTracker().disconnectSubframe(*this);
 }
 
 void HTMLFrameOwnerElement::disconnectContentFrame()
 {
     // FIXME: Currently we don't do this in removedFrom because this causes an
     // unload event in the subframe which could execute script that could then
     // reach up into this document and then attempt to look back down. We should
     // see if this behavior is really needed as Gecko does not allow this.
     if (RefPtrWillBeRawPtr<Frame> frame = contentFrame()) {
         frame->detach(FrameDetachType::Remove);
@@ skipping 124 matching lines @@
 DEFINE_TRACE(HTMLFrameOwnerElement)
 {
     visitor->trace(m_contentFrame);
     visitor->trace(m_widget);
     HTMLElement::trace(visitor);
     FrameOwner::trace(visitor);
 }
 
 
 } // namespace blink