Use ChildFrameDisconnector when detaching child frames of a LocalFrame.

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 178 matching lines @@
 
     ASSERT(owner());
     toHTMLFrameOwnerElement(owner())->setNeedsCompositingUpdate();
 }
 
 void RemoteFrame::advanceFocus(WebFocusType type, LocalFrame* source)
 {
     client()->advanceFocus(type, source);
 }
 
+void RemoteFrame::detachChildren()
+{
+    using FrameVector = HeapVector<Member<Frame>>;
+    FrameVector childrenToDetach;
+    childrenToDetach.reserveCapacity(tree().childCount());
+    for (Frame* child = tree().firstChild(); child; child = child->tree().nextSibling())
+        childrenToDetach.append(child);
+    for (const auto& child : childrenToDetach)
+        child->detach(FrameDetachType::Remove);
+}
+
 } // namespace blink