Move ReadFileToString to the base namespace.

chrome/test/perf/startup_test.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/environment.h"
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
@@ skipping 99 matching lines @@
 
     const base::FilePath pref_template_path(user_data_dir().
         AppendASCII("Default").
         AppendASCII("PreferencesTemplate"));
     const base::FilePath pref_path(user_data_dir().
         AppendASCII(TestingProfile::kTestUserProfileDir).
         AppendASCII("Preferences"));
 
     // Read in preferences template.
     std::string pref_string;
-    EXPECT_TRUE(file_util::ReadFileToString(pref_template_path, &pref_string));
+    EXPECT_TRUE(base::ReadFileToString(pref_template_path, &pref_string));
     string16 format_string = ASCIIToUTF16(pref_string);
 
     // Make sure temp directory has the proper format for writing to prefs file.
 #if defined(OS_POSIX)
     std::wstring user_data_dir_w(ASCIIToWide(user_data_dir().value()));
 #elif defined(OS_WIN)
     std::wstring user_data_dir_w(user_data_dir().value());
     // In Windows, the FilePath will write '\' for the path separators; change
     // these to a separator that won't trigger escapes.
     std::replace(user_data_dir_w.begin(),
@@ skipping 341 matching lines @@
 }
 
 TEST_F(StartupTest, ProfilingScript1) {
   SetUpWithFileURL();
   SetUpWithProfiling();
   RunStartupTest("warm", "profiling_scripts1", WARM, NOT_IMPORTANT,
                  PerfUITestSuite::DEFAULT_THEME, 1, 0);
 }
 
 }  // namespace