base: Convert the remaining uses of MessageLoop::RunUntilIdle to RunLoop variant.

base/files/important_file_writer_unittest.cc

 // Copyright (c) 2012 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 "base/files/important_file_writer.h"
 
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/run_loop.h"
 #include "base/threading/thread.h"
 #include "base/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 namespace {
 
 std::string GetFileContent(const FilePath& path) {
   std::string content;
@@ skipping 33 matching lines @@
 
  private:
   ScopedTempDir temp_dir_;
 };
 
 TEST_F(ImportantFileWriterTest, Basic) {
   ImportantFileWriter writer(file_,
                              MessageLoopProxy::current());
   EXPECT_FALSE(file_util::PathExists(writer.path()));
   writer.WriteNow("foo");
-  loop_.RunUntilIdle();
+  RunLoop().RunUntilIdle();
 
   ASSERT_TRUE(file_util::PathExists(writer.path()));
   EXPECT_EQ("foo", GetFileContent(writer.path()));
 }
 
 TEST_F(ImportantFileWriterTest, ScheduleWrite) {
   ImportantFileWriter writer(file_,
                              MessageLoopProxy::current());
   writer.set_commit_interval(TimeDelta::FromMilliseconds(25));
   EXPECT_FALSE(writer.HasPendingWrite());
@@ skipping 39 matching lines @@
   MessageLoop::current()->PostDelayedTask(
       FROM_HERE,
       MessageLoop::QuitWhenIdleClosure(),
       TimeDelta::FromMilliseconds(100));
   MessageLoop::current()->Run();
   ASSERT_TRUE(file_util::PathExists(writer.path()));
   EXPECT_EQ("baz", GetFileContent(writer.path()));
 }
 
 }  // namespace base