Move Frame pointer to be held by DOMWindow base class.

third_party/WebKit/Source/core/frame/RemoteFrame.cpp

 // 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/frame/RemoteFrame.h"
 
 #include "bindings/core/v8/WindowProxy.h"
 #include "bindings/core/v8/WindowProxyManager.h"
 #include "core/dom/RemoteSecurityContext.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 85 matching lines @@
   if (!client())
     return;
 
   // Clean up the frame's view if needed. A remote frame only has a view if
   // the parent is a local frame.
   if (m_view)
     m_view->dispose();
   client()->willBeDetached();
   m_windowProxyManager->clearForClose();
   setView(nullptr);
+  // ... the RemoteDOMWindow will need to be informed of detachment,
+  // as otherwise it will keep a strong reference back to this RemoteFrame.
+  // That combined with wrappers (owned and kept alive by RemoteFrame) keeping
+  // persistent strong references to RemoteDOMWindow will prevent the GCing
+  // of all these objects. Break the cycle by notifying of detachment.
+  toRemoteDOMWindow(m_domWindow)->frameDetached();

[dcheng, 2017/01/13 03:38:22]

I moved this out of setView() because it seems a little unrelated to have it
hooked in there.

   if (m_webLayer)
     setWebLayer(nullptr);
   Frame::detach(type);
 }
 
 bool RemoteFrame::prepareForCommit() {
   detachChildren();
   return !!host();
 }
 
@@ skipping 21 matching lines @@
 
 void RemoteFrame::visibilityChanged(bool visible) {
   if (client())
     client()->visibilityChanged(visible);
 }
 
 void RemoteFrame::setView(RemoteFrameView* view) {
   // Oilpan: as RemoteFrameView performs no finalization actions,
   // no explicit dispose() of it needed here. (cf. FrameView::dispose().)
   m_view = view;
-
-  // ... the RemoteDOMWindow will need to be informed of detachment,
-  // as otherwise it will keep a strong reference back to this RemoteFrame.
-  // That combined with wrappers (owned and kept alive by RemoteFrame) keeping
-  // persistent strong references to RemoteDOMWindow will prevent the GCing
-  // of all these objects. Break the cycle by notifying of detachment.
-  if (!m_view)
-    toRemoteDOMWindow(m_domWindow)->frameDetached();
 }
 
 void RemoteFrame::createView() {
   // If the RemoteFrame does not have a LocalFrame parent, there's no need to
   // create a widget for it.
   if (!deprecatedLocalOwner())
     return;
 
   ASSERT(!deprecatedLocalOwner()->ownedWidget());
 
@@ skipping 31 matching lines @@
   FrameVector childrenToDetach;
   childrenToDetach.reserveCapacity(tree().childCount());
   for (Frame* child = tree().firstChild(); child;
        child = child->tree().nextSibling())
     childrenToDetach.push_back(child);
   for (const auto& child : childrenToDetach)
     child->detach(FrameDetachType::Remove);
 }
 
 }  // namespace blink