Remove calls to MessageLoop::current() in tools.

tools/gn/loader_unittest.cc

 // Copyright (c) 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 <map>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/err.h"
 #include "tools/gn/loader.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/parser.h"
 #include "tools/gn/scheduler.h"
 #include "tools/gn/tokenizer.h"
 
@@ skipping 157 matching lines @@
   loader->Load(third_file, LocationRange(), second_tc);
   EXPECT_TRUE(mock_ifm_.HasOnePending(build_config));
 
   // Running the build config file should make our third file pending.
   mock_ifm_.IssueAllPending();
   base::RunLoop().RunUntilIdle();
   EXPECT_TRUE(mock_ifm_.HasTwoPending(second_file, third_file));
 
   EXPECT_FALSE(scheduler_.is_failed());
 }