POSIX: Don't allow onunload handlers to hang a renderer forever.

chrome/common/ipc_channel_proxy.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef CHROME_COMMON_IPC_CHANNEL_PROXY_H__
 #define CHROME_COMMON_IPC_CHANNEL_PROXY_H__
 
 #include <vector>
 #include "base/lock.h"
 #include "base/ref_counted.h"
@@ skipping 46 matching lines @@
 
     // Called on the background thread when the filter has been removed from
     // the ChannelProxy and when the Channel is closing.  After a filter is
     // removed, it will not be called again.
     virtual void OnFilterRemoved() {}
 
     // Called to inform the filter that the IPC channel is connected and we
     // have received the internal Hello message from the peer.
     virtual void OnChannelConnected(int32 peer_pid) {}
 
+    // Called when there is an error on the channel, typically that the channel
+    // has been closed.
+    virtual void OnChannelError() {}
+
     // Called to inform the filter that the IPC channel will be destroyed.
     // OnFilterRemoved is called immediately after this.
     virtual void OnChannelClosing() {}
 
     // Return true to indicate that the message was handled, or false to let
     // the message be handled in the default way.
     virtual bool OnMessageReceived(const Message& message) {
       return false;
     }
   };
@@ skipping 120 matching lines @@
 
   // By maintaining this indirection (ref-counted) to our internal state, we
   // can safely be destroyed while the background thread continues to do stuff
   // that involves this data.
   scoped_refptr<Context> context_;
 };
 
 }  // namespace IPC
 
 #endif  // CHROME_COMMON_IPC_CHANNEL_PROXY_H__