Fix Mojo broker crash on Windows.

mojo/edk/system/child_broker_host.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/child_broker_host.h"
 
 #include <stdint.h>
 
 #include <utility>
 
@@ skipping 87 matching lines @@
   memset(&data, 0, sizeof(data));
   data.type = PEER_PIPE_CONNECTED;
   data.pipe_id = pipe_id;
   data.process_id = process_id;
   scoped_ptr<MessageInTransit> message(new MessageInTransit(
       MessageInTransit::Type::MESSAGE, sizeof(data), &data));
   message->set_route_id(kBrokerRouteId);
   child_channel_->channel()->WriteMessage(std::move(message));
 }
 
+void ChildBrokerHost::PeerDied(uint64_t pipe_id) {
+  if (!child_channel_)
+    return;  // Can happen at process shutdown on Windows.
+  PeerDiedMessage data;
+  memset(&data, 0, sizeof(data));
+  data.type = PEER_DIED;
+  data.pipe_id = pipe_id;
+  scoped_ptr<MessageInTransit> message(new MessageInTransit(
+      MessageInTransit::Type::MESSAGE, sizeof(data), &data));
+  message->set_route_id(kBrokerRouteId);
+  child_channel_->channel()->WriteMessage(std::move(message));
+}
+
 ChildBrokerHost::~ChildBrokerHost() {
   DCHECK(internal::g_io_thread_task_runner->RunsTasksOnCurrentThread());
   BrokerState::GetInstance()->ChildBrokerHostDestructed(this);
   if (child_channel_)
     child_channel_->RemoveRoute(kBrokerRouteId);
 }
 
 void ChildBrokerHost::InitOnIO(
     ScopedPlatformHandle parent_async_channel_handle) {
   child_channel_ = new RoutedRawChannel(
@@ skipping 189 matching lines @@
   BOOL result = DuplicateHandle(child_process_.Handle(), handle,
                                 base::GetCurrentProcessHandle(), &rv, 0, FALSE,
                                 DUPLICATE_SAME_ACCESS | DUPLICATE_CLOSE_SOURCE);
   DCHECK(result);
   return rv;
 }
 #endif
 
 }  // namespace edk
 }  // namespace mojo