Clear RenderFrameImpl::frame_ pointer after deleting it.

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 887 matching lines @@
 
 #if defined(OS_MACOSX) || defined(OS_ANDROID)
 void RenderFrameImpl::DidHideExternalPopupMenu() {
   // We need to clear external_popup_menu_ as soon as ExternalPopupMenu::close
   // is called. Otherwise, createExternalPopupMenu() for new popup will fail.
   external_popup_menu_.reset();
 }
 #endif
 
 bool RenderFrameImpl::OnMessageReceived(const IPC::Message& msg) {
+  // We may get here while detaching, when the WebFrame has been deleted.  Do
+  // not process any messages in this state.
+  if (!frame_)
+    return false;
+
   // TODO(kenrb): document() should not be null, but as a transitional step
   // we have RenderFrameProxy 'wrapping' a RenderFrameImpl, passing messages
   // to this method. This happens for a top-level remote frame, where a
   // document-less RenderFrame is replaced by a RenderFrameProxy but kept
   // around and is still able to receive messages.
   if (!frame_->document().isNull())
     GetContentClient()->SetActiveURL(frame_->document().url());
 
   ObserverListBase<RenderFrameObserver>::Iterator it(observers_);
   RenderFrameObserver* observer;
@@ skipping 1123 matching lines @@
   // containing RenderViewHost (so that they have the same lifetime), so only
   // removal from the map is needed and no deletion.
   FrameMap::iterator it = g_frame_map.Get().find(frame);
   CHECK(it != g_frame_map.Get().end());
   CHECK_EQ(it->second, this);
   g_frame_map.Get().erase(it);
 
   if (is_subframe)
     frame->parent()->removeChild(frame);
 
-  // |frame| is invalid after here.
+  // |frame| is invalid after here.  Be sure to clear frame_ as well, since this
+  // object may not be deleted immediately and other methods may try to access
+  // it.
   frame->close();
+  frame_ = nullptr;
 
   if (is_subframe) {
     delete this;
     // Object is invalid after this point.
   }
 }
 
 void RenderFrameImpl::frameFocused() {
   Send(new FrameHostMsg_FrameFocused(routing_id_));
 }
@@ skipping 2295 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