Add //mojo/edk/platform and move platform_task_runners.h there.

mojo/edk/system/slave_connection_manager.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/slave_connection_manager.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "mojo/edk/system/connection_manager_messages.h"
 #include "mojo/edk/system/message_in_transit.h"
 #include "mojo/edk/util/make_unique.h"
 
+using mojo::platform::TaskRunner;
 using mojo::util::MutexLocker;
 using mojo::util::RefPtr;
 
 namespace mojo {
 namespace system {
 
 // SlaveConnectionManager ------------------------------------------------------
 
 SlaveConnectionManager::SlaveConnectionManager(
     embedder::PlatformSupport* platform_support)
@@ skipping 11 matching lines @@
   DCHECK(!slave_process_delegate_);
   DCHECK(!private_thread_.message_loop());
   DCHECK_EQ(awaiting_ack_type_, NOT_AWAITING_ACK);
   DCHECK(!ack_result_);
   DCHECK(!ack_peer_process_identifier_);
   DCHECK(!ack_is_first_);
   DCHECK(!ack_platform_handle_);
 }
 
 void SlaveConnectionManager::Init(
-    RefPtr<embedder::PlatformTaskRunner>&& delegate_thread_task_runner,
+    RefPtr<TaskRunner>&& delegate_thread_task_runner,
     embedder::SlaveProcessDelegate* slave_process_delegate,
     embedder::ScopedPlatformHandle platform_handle) {
   DCHECK(delegate_thread_task_runner);
   DCHECK(slave_process_delegate);
   DCHECK(platform_handle.is_valid());
   DCHECK(!delegate_thread_task_runner_);
   DCHECK(!slave_process_delegate_);
   DCHECK(!private_thread_.message_loop());
 
   delegate_thread_task_runner_ = std::move(delegate_thread_task_runner);
@@ skipping 279 matching lines @@
 }
 
 void SlaveConnectionManager::AssertOnPrivateThread() const {
   // This should only be called after |Init()| and before |Shutdown()|.
   DCHECK(private_thread_.message_loop());
   DCHECK_EQ(base::MessageLoop::current(), private_thread_.message_loop());
 }
 
 }  // namespace system
 }  // namespace mojo