Mojo: Refactor some message pipe stuff.

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 <stdint.h>
 
 #include <deque>
@@ skipping 28 matching lines @@
 //    run, it gets a remote ID.
 class MOJO_SYSTEM_IMPL_EXPORT ProxyMessagePipeEndpoint
     : public MessagePipeEndpoint {
  public:
   ProxyMessagePipeEndpoint();
   virtual ~ProxyMessagePipeEndpoint();
 
   // |MessagePipeEndpoint| implementation:
   virtual void Close() OVERRIDE;
   virtual void OnPeerClose() OVERRIDE;
-  virtual MojoResult CanEnqueueMessage(
-      const MessageInTransit* message,
+  virtual MojoResult EnqueueMessage(
+      MessageInTransit* message,
       const std::vector<Dispatcher*>* dispatchers) OVERRIDE;
-  virtual void EnqueueMessage(
-      MessageInTransit* message,
-      std::vector<scoped_refptr<Dispatcher> >* dispatchers) OVERRIDE;
   virtual void Attach(scoped_refptr<Channel> channel,
                       MessageInTransit::EndpointId local_id) OVERRIDE;
   virtual void Run(MessageInTransit::EndpointId remote_id) OVERRIDE;
 
  private:
   bool is_attached() const {
     return !!channel_.get();
   }
 
   bool is_running() const {
     return remote_id_ != MessageInTransit::kInvalidEndpointId;
   }
 
+  MojoResult CanEnqueueDispatchers(const std::vector<Dispatcher*>* dispatchers);
+  // |dispatchers| should be non-null only if it's nonempty, in which case the
+  // dispatchers should have been preflighted by |CanEnqueueDispatchers()|.
+  void EnqueueMessageInternal(MessageInTransit* message,
+                              const std::vector<Dispatcher*>* dispatchers);
+
 #ifdef NDEBUG
   void AssertConsistentState() const {}
 #else
   void AssertConsistentState() const;
 #endif
 
   // This should only be set if we're attached.
   scoped_refptr<Channel> channel_;
 
   // |local_id_| should be set to something other than
@@ skipping 13 matching lines @@
   // not ready to send them yet.
   std::deque<MessageInTransit*> paused_message_queue_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyMessagePipeEndpoint);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_PROXY_MESSAGE_PIPE_ENDPOINT_H_