Make it possible to write a message pipe endpoint's peer into it.

mojo/edk/system/core_test_base.cc

 // 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.
 
 #include "mojo/edk/system/core_test_base.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "mojo/edk/embedder/simple_platform_support.h"
@@ skipping 173 matching lines @@
     mutex().AssertHeld();
     if (signals_state)
       *signals_state = HandleSignalsState();
   }
 
   void CancelAllAwakablesNoLock() override {
     info_->IncrementCancelAllAwakablesCallCount();
     mutex().AssertHeld();
   }
 
-  RefPtr<Dispatcher> CreateEquivalentDispatcherAndCloseImplNoLock() override {
+  RefPtr<Dispatcher> CreateEquivalentDispatcherAndCloseImplNoLock(
+      MessagePipe* /*message_pipe*/,
+      unsigned /*port*/) override {
+    CancelAllAwakablesNoLock();
     return Create(info_);
   }
 
   CoreTestBase::MockHandleInfo* const info_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(MockDispatcher);
 };
 
 }  // namespace
 
@@ skipping 220 matching lines @@
 }
 
 void CoreTestBase_MockHandleInfo::AwakableWasAdded(Awakable* awakable) {
   MutexLocker locker(&mutex_);
   added_awakables_.push_back(awakable);
 }
 
 }  // namespace test
 }  // namespace system
 }  // namespace mojo