Move IsStringUTF8/ASCII to base namespace

ppapi/shared_impl/file_ref_util.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 "ppapi/shared_impl/file_ref_util.h"
 
 #include "base/files/file_path.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 
@@ skipping 18 matching lines @@
 #else
 #error "Unsupported platform."
 #endif
 }
 
 bool IsValidInternalPath(const std::string& path) {
   // We check that:
   //   The path starts with '/'
   //   The path must contain valid UTF-8 characters.
   //   It must not FilePath::ReferencesParent().
-  if (path.empty() || !IsStringUTF8(path) || path[0] != '/')
+  if (path.empty() || !base::IsStringUTF8(path) || path[0] != '/')
     return false;
   base::FilePath file_path = base::FilePath::FromUTF8Unsafe(path);
   if (file_path.ReferencesParent())
     return false;
   return true;
 }
 
 bool IsValidExternalPath(const base::FilePath& path) {
   return !path.empty() && !path.ReferencesParent();
 }
 
 void NormalizeInternalPath(std::string* path) {
   if (path->size() > 1 && path->at(path->size() - 1) == '/')
     path->erase(path->size() - 1, 1);
 }
 
 }  // namespace ppapi