Don't process messages sent to dead routing ids.

content/browser/renderer_host/render_widget_host_impl.cc

 // Copyright (c) 2012 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/browser/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <set>
 #include <utility>
 
@@ skipping 426 matching lines @@
   }
 
   Destroy();
 }
 
 bool RenderWidgetHostImpl::IsLoading() const {
   return is_loading_;
 }
 
 bool RenderWidgetHostImpl::OnMessageReceived(const IPC::Message &msg) {
+  // Only process messages if the RenderWidget is alive.
+  if (!renderer_initialized())
+    return false;
+
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderWidgetHostImpl, msg)
     IPC_MESSAGE_HANDLER(FrameHostMsg_RenderProcessGone, OnRenderProcessGone)
     IPC_MESSAGE_HANDLER(InputHostMsg_QueueSyntheticGesture,
                         OnQueueSyntheticGesture)
     IPC_MESSAGE_HANDLER(InputHostMsg_ImeCancelComposition,
                         OnImeCancelComposition)
     IPC_MESSAGE_HANDLER(ViewHostMsg_Close, OnClose)
     IPC_MESSAGE_HANDLER(ViewHostMsg_UpdateScreenRects_ACK,
                         OnUpdateScreenRectsAck)
@@ skipping 1785 matching lines @@
 }
 
 #if defined(OS_WIN)
 gfx::NativeViewAccessible
     RenderWidgetHostImpl::GetParentNativeViewAccessible() {
   return delegate_ ? delegate_->GetParentNativeViewAccessible() : NULL;
 }
 #endif
 
 }  // namespace content