Fix memory leak in unittests with new Mojo EDK.

mojo/edk/system/message_pipe_dispatcher.cc

 // Copyright 2015 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 "mojo/edk/system/message_pipe_dispatcher.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 418 matching lines @@
 #endif
 }
 
 void MessagePipeDispatcher::CancelAllAwakablesNoLock() {
   lock().AssertAcquired();
   awakable_list_.CancelAll();
 }
 
 void MessagePipeDispatcher::CloseImplNoLock() {
   lock().AssertAcquired();
+  // This early circuit fixes leak in unit tests. There's nothing to do in the
+  // posted task.
+  if (!transferable_ && non_transferable_state_ == CLOSED)
+    return;
+
   // We take a manual refcount because at shutdown, the task below might not get
-  // a chance to execute. If that happens, the RawChannel's will still call our
+  // a chance to execute. If that happens, the RawChannel will still call our
   // OnError method because it always runs (since it watches thread
   // destruction). So to avoid UAF, manually add a reference and only release it
   // if the task runs.
   AddRef();
   internal::g_io_thread_task_runner->PostTask(
       FROM_HERE, base::Bind(&MessagePipeDispatcher::CloseOnIO, this));
 }
 
 void MessagePipeDispatcher::SerializeInternal() {
   serialized_ = true;
@@ skipping 546 matching lines @@
   // PostTask since the broker can call us back synchronously.
   internal::g_io_thread_task_runner->PostTask(
       FROM_HERE,
       base::Bind(&Broker::ConnectMessagePipe,
                  base::Unretained(internal::g_broker), pipe_id_,
                  base::Unretained(this)));
 }
 
 }  // namespace edk
 }  // namespace mojo