EDK: Remove mojo::platform::MessageLoopForIO and add PlatformHandleWatcher.

mojo/edk/base_edk/test_message_loops.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.
 
 // This file implements the factory functions declared in
 // //mojo/edk/platform/test_message_loops.h (using
 // |mojo::platform::MessageLoop|s based on //base, i.e., using
 // |base_edk::PlatformMessageLoopImpl|).
 
 #include "mojo/edk/platform/test_message_loops.h"
 
+#include <utility>
+
 #include "mojo/edk/base_edk/platform_message_loop_for_io_impl.h"
 #include "mojo/edk/base_edk/platform_message_loop_impl.h"
 #include "mojo/edk/util/make_unique.h"
 
 using mojo::util::MakeUnique;
 
 namespace mojo {
 namespace platform {
 namespace test {
 
 std::unique_ptr<MessageLoop> CreateTestMessageLoop() {
   return MakeUnique<base_edk::PlatformMessageLoopImpl>();
 }
 
-std::unique_ptr<MessageLoopForIO> CreateTestMessageLoopForIO() {
-  return MakeUnique<base_edk::PlatformMessageLoopForIOImpl>();
+std::unique_ptr<MessageLoop> CreateTestMessageLoopForIO(
+    PlatformHandleWatcher** platform_handle_watcher) {
+  auto rv = MakeUnique<base_edk::PlatformMessageLoopForIOImpl>();
+  *platform_handle_watcher = rv.get();
+  return std::move(rv);
 }
 
 }  // namespace test
 }  // namespace platform
 }  // namespace mojo