Invalidate the previous frame when the window object is cleared.

content/renderer/render_frame_impl.cc

 // Copyright 2013 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 "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 2339 matching lines @@
   // navigation without valid HistoryItem state, WebCore will think it is a
   // new navigation.
   navigation_state->set_request_committed(true);
 
   SendDidCommitProvisionalLoad(frame);
 
   // Check whether we have new encoding name.
   UpdateEncoding(frame, frame->view()->pageEncoding().utf8());
 }
 
+void RenderFrameImpl::didCreateNewDocument(blink::WebLocalFrame* frame) {
+  DCHECK(!frame_ || frame_ == frame);

[dcheng, 2014/11/11 16:50:16]

This assert should be more aggressive. We should never call this and pass a null
frame parameter.

[robwu, 2014/11/11 21:43:59]

This DCHECK does not test whether the passed-in pointer is a non-null pointer,
but it shows that frame ought to be equal to |frame_| if set.
This whole class assumes that the passed-in WebLocalFrame* pointer is non-null,
so I don't think that we need a CHECK(!frame);
If you look at src/third_party/WebKit/Source/web/FrameLoaderClientImpl.cpp, it
becomes obvious that that class also assumes that m_webFrame is always non-null,
so again I see no point im adding a stronger assertion here.

+
+  FOR_EACH_OBSERVER(RenderViewObserver, render_view_->observers(),
+                    DidCreateNewDocument(frame));
+}
+
 void RenderFrameImpl::didClearWindowObject(blink::WebLocalFrame* frame) {
   DCHECK(!frame_ || frame_ == frame);
   // TODO(nasko): Move implementation here. Needed state:
   // * enabled_bindings_
   // * dom_automation_controller_
   // * stats_collection_controller_
 
   render_view_->didClearWindowObject(frame);
 
   if (render_view_->GetEnabledBindings() & BINDINGS_POLICY_DOM_AUTOMATION)
@@ skipping 1779 matching lines @@
 
 #if defined(ENABLE_BROWSER_CDMS)
 RendererCdmManager* RenderFrameImpl::GetCdmManager() {
   if (!cdm_manager_)
     cdm_manager_ = new RendererCdmManager(this);
   return cdm_manager_;
 }
 #endif  // defined(ENABLE_BROWSER_CDMS)
 
 }  // namespace content