Mojo: Move the paused message queue from ProxyMessagePipeEndpoint to ChannelEndpoint.

mojo/system/channel_endpoint.h

 // Copyright 2014 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_CHANNEL_ENDPOINT_H_
 #define MOJO_SYSTEM_CHANNEL_ENDPOINT_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "mojo/system/message_in_transit.h"
+#include "mojo/system/message_in_transit_queue.h"
 #include "mojo/system/system_impl_export.h"
 
 namespace mojo {
 namespace system {
 
 class Channel;
 class MessagePipe;
 
 // TODO(vtl): The plan:
 //   - (Done.) Move |Channel::Endpoint| to |ChannelEndpoint|. Make it
@@ skipping 82 matching lines @@
 //         "remove" message from the other side (if the other side is closed
 //         simultaneously, and both sides send "remove" messages). In that
 //         case, it must still remain alive until it receives the "remove
 //         ack" (and it must ack the "remove" message that it received).
 class MOJO_SYSTEM_IMPL_EXPORT ChannelEndpoint
     : public base::RefCountedThreadSafe<ChannelEndpoint> {
  public:
   // TODO(vtl): More comments....
   ChannelEndpoint(MessagePipe* message_pipe, unsigned port);
 
+  // Takes messages from the given |MessageInTransitQueue|. This must be called
+  // before this object is attached to a channel, and before anyone has a chance
+  // to enqueue any messages.
+  void TakeMessages(MessageInTransitQueue* message_queue);
+
   // Methods called by |MessagePipe| (via |ProxyMessagePipeEndpoint|):
 
   // TODO(vtl): This currently only works if we're "running". We'll move the
   // "paused message queue" here (will this be needed when we have
   // locally-allocated remote IDs?).
   bool EnqueueMessage(scoped_ptr<MessageInTransit> message);
 
   void DetachFromMessagePipe();
 
   // Methods called by |Channel|:
@@ skipping 38 matching lines @@
   // TODO(vtl): Move the things above under lock.
   // Protects the members below.
   base::Lock lock_;
 
   // |channel_| must be alive whenever this is non-null. Before the |channel_|
   // gives up its reference to this object, it will call |DetachFromChannel()|.
   Channel* channel_;
   MessageInTransit::EndpointId local_id_;
   MessageInTransit::EndpointId remote_id_;
 
+  // This queue is used before we're running on a channel and ready to send
+  // messages.
+  MessageInTransitQueue paused_message_queue_;
+
   DISALLOW_COPY_AND_ASSIGN(ChannelEndpoint);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_CHANNEL_ENDPOINT_H_