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

mojo/edk/system/platform_handle_dispatcher.cc

 // 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.
 
 #include "mojo/edk/system/platform_handle_dispatcher.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 68 matching lines @@
     : platform_handle_(platform_handle.Pass()) {}
 
 PlatformHandleDispatcher::~PlatformHandleDispatcher() {}
 
 void PlatformHandleDispatcher::CloseImplNoLock() {
   mutex().AssertHeld();
   platform_handle_.reset();
 }
 
 RefPtr<Dispatcher>
-PlatformHandleDispatcher::CreateEquivalentDispatcherAndCloseImplNoLock() {
+PlatformHandleDispatcher::CreateEquivalentDispatcherAndCloseImplNoLock(
+    MessagePipe* /*message_pipe*/,
+    unsigned /*port*/) {
   mutex().AssertHeld();
+  CancelAllAwakablesNoLock();
   return Create(platform_handle_.Pass());
 }
 
 void PlatformHandleDispatcher::StartSerializeImplNoLock(
     Channel* /*channel*/,
     size_t* max_size,
     size_t* max_platform_handles) {
   AssertHasOneRef();  // Only one ref => no need to take the lock.
   *max_size = sizeof(SerializedPlatformHandleDispatcher);
   *max_platform_handles = 1;
@@ skipping 14 matching lines @@
   } else {
     serialization->platform_handle_index = kInvalidPlatformHandleIndex;
   }
 
   *actual_size = sizeof(SerializedPlatformHandleDispatcher);
   return true;
 }
 
 }  // namespace system
 }  // namespace mojo