Call LocalDOMWindow::clearDocument when a frame gets detached

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

Index: third_party/WebKit/Source/core/frame/LocalFrame.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalFrame.cpp b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
index 2c1032aecb501ccaef1f27cde55e16e3374f9b11..25f6339b811b44038a1aff4516419c6fb60506d7 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
@@ -398,6 +398,8 @@ void LocalFrame::detach(FrameDetachType type) {
   // frame on a detached DOM tree, which is bad.
   SubframeLoadingDisabler disabler(*document());
   m_loader.dispatchUnloadEvent();
+  if (!client())
+    return;
   detachChildren();
 
   // All done if detaching the subframes brought about a detach of this frame
@@ -485,7 +487,7 @@ bool LocalFrame::shouldClose() {
 }
 
 void LocalFrame::detachChildren() {
-  DCHECK(m_loader.stateMachine()->creatingInitialEmptyDocument() || document());
+  CHECK(m_loader.stateMachine()->creatingInitialEmptyDocument() || document());
 
   if (Document* document = this->document())
     ChildFrameDisconnector(*document).disconnect();