Move ReadFileToString to the base namespace.

ui/gfx/color_profile_win.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 "ui/gfx/color_profile.h"
 
 #include <windows.h>
 
 #include "base/file_util.h"
 
 namespace gfx {
 
 void ReadColorProfile(std::vector<char>* profile) {
   // TODO: support multiple monitors.
   HDC screen_dc = GetDC(NULL);
   DWORD path_len = MAX_PATH;
   WCHAR path[MAX_PATH + 1];
 
   BOOL res = GetICMProfile(screen_dc, &path_len, path);
   ReleaseDC(NULL, screen_dc);
   if (!res)
     return;
   std::string profileData;
-  if (!file_util::ReadFileToString(base::FilePath(path), &profileData))
+  if (!base::ReadFileToString(base::FilePath(path), &profileData))
     return;
   size_t length = profileData.size();
   if (length > gfx::kMaxProfileLength)
     return;
   if (length < gfx::kMinProfileLength)
     return;
   profile->assign(profileData.data(), profileData.data() + length);
 }
 
 }  // namespace gfx