Remove <iostream> where possible.

base/file_util_unittest.cc

 // Copyright (c) 2010 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 "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <winioctl.h>
 #include <shellapi.h>
 #include <shlobj.h>
 #include <tchar.h>
 #endif
 
 #include <fstream>
-#include <iostream>
 #include <set>
 
 #include "base/base_paths.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/platform_thread.h"
 #include "base/scoped_handle.h"
 #include "base/time.h"
@@ skipping 1831 matching lines @@
   EXPECT_TRUE(file_util::IsDirectoryEmpty(empty_dir));
 
   FilePath foo(empty_dir.Append(FILE_PATH_LITERAL("foo.txt")));
   std::string bar("baz");
   ASSERT_TRUE(file_util::WriteFile(foo, bar.c_str(), bar.length()));
 
   EXPECT_FALSE(file_util::IsDirectoryEmpty(empty_dir));
 }
 
 }  // namespace