Move ReadFileToString to the base namespace.

webkit/support/test_webkit_platform_support.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 "webkit/support/test_webkit_platform_support.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 296 matching lines @@
         TestViewType type) {
   DCHECK_EQ(TestViewTypeUnitTest, type);
   return createLayerTreeViewForTesting();
 }
 
 WebKit::WebData TestWebKitPlatformSupport::readFromFile(
     const WebKit::WebString& path) {
   base::FilePath file_path = base::FilePath::FromUTF16Unsafe(path);
 
   std::string buffer;
-  file_util::ReadFileToString(file_path, &buffer);
+  base::ReadFileToString(file_path, &buffer);
 
   return WebKit::WebData(buffer.data(), buffer.size());
 }