Mojo: Don't do any work in ProxyMessagePipeEndpoint's destructor.

mojo/system/proxy_message_pipe_endpoint.h

 // 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.
 
 #ifndef MOJO_SYSTEM_PROXY_MESSAGE_PIPE_ENDPOINT_H_
 #define MOJO_SYSTEM_PROXY_MESSAGE_PIPE_ENDPOINT_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "mojo/system/message_in_transit.h"
@@ skipping 19 matching lines @@
 class MOJO_SYSTEM_IMPL_EXPORT ProxyMessagePipeEndpoint
     : public MessagePipeEndpoint {
  public:
   explicit ProxyMessagePipeEndpoint(ChannelEndpoint* channel_endpoint);
   virtual ~ProxyMessagePipeEndpoint();
 
   // |MessagePipeEndpoint| implementation:
   virtual Type GetType() const override;
   virtual bool OnPeerClose() override;
   virtual void EnqueueMessage(scoped_ptr<MessageInTransit> message) override;
+  virtual void Close() override;
 
  private:
+  void DetachIfNecessary();
+
   scoped_refptr<ChannelEndpoint> channel_endpoint_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyMessagePipeEndpoint);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_PROXY_MESSAGE_PIPE_ENDPOINT_H_