Use ScopedTaskEnvironment instead of MessageLoop in content unit tests.

content/browser/fileapi/transient_file_util_unittest.cc

 // Copyright 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 <memory>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "content/public/test/test_file_system_context.h"
 #include "storage/browser/blob/scoped_file.h"
 #include "storage/browser/fileapi/file_system_context.h"
 #include "storage/browser/fileapi/file_system_operation_context.h"
 #include "storage/browser/fileapi/isolated_context.h"
 #include "storage/browser/fileapi/transient_file_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using storage::FileSystemURL;
 
@@ skipping 39 matching lines @@
   std::unique_ptr<storage::FileSystemOperationContext> NewOperationContext() {
     return base::MakeUnique<storage::FileSystemOperationContext>(
         file_system_context_.get());
   }
 
   storage::FileSystemFileUtil* file_util() {
     return transient_file_util_.get();
   }
 
  private:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   base::ScopedTempDir data_dir_;
   scoped_refptr<storage::FileSystemContext> file_system_context_;
   std::unique_ptr<storage::TransientFileUtil> transient_file_util_;
 
   DISALLOW_COPY_AND_ASSIGN(TransientFileUtilTest);
 };
 
 TEST_F(TransientFileUtilTest, TransientFile) {
   FileSystemURL temp_url;
   base::FilePath temp_path;
@@ skipping 30 matching lines @@
   base::RunLoop().RunUntilIdle();
 
   // Now the temporary file and the transient filesystem must be gone too.
   ASSERT_FALSE(base::PathExists(temp_path));
   ASSERT_EQ(base::File::FILE_ERROR_NOT_FOUND,
             file_util()->GetFileInfo(NewOperationContext().get(),
                                      temp_url, &file_info, &path));
 }
 
 }  // namespace content