Move IsStringUTF8/ASCII to base namespace

net/base/filename_util.cc

Index: net/base/filename_util.cc
diff --git a/net/base/filename_util.cc b/net/base/filename_util.cc
index ed4831d8b46375f6a4590a933810dfd4f857adb6..3c9aef885430e90bc240f480800ab933710930de 100644
--- a/net/base/filename_util.cc
+++ b/net/base/filename_util.cc
@@ -72,7 +72,7 @@ std::string GetFileNameFromURL(const GURL& url,
 
   // The URL's path should be escaped UTF-8, but may not be.
   std::string decoded_filename = unescaped_url_filename;
-  if (!IsStringUTF8(decoded_filename)) {
+  if (!base::IsStringUTF8(decoded_filename)) {
     // TODO(jshin): this is probably not robust enough. To be sure, we need
     // encoding detection.
     base::string16 utf16_output;
@@ -311,7 +311,7 @@ bool FileURLToFilePath(const GURL& url, base::FilePath* file_path) {
       UnescapeRule::SPACES | UnescapeRule::URL_SPECIAL_CHARS);
 
 #if defined(OS_WIN)
-  if (IsStringUTF8(path)) {
+  if (base::IsStringUTF8(path)) {
     file_path_str.assign(base::UTF8ToWide(path));
     // We used to try too hard and see if |path| made up entirely of
     // the 1st 256 characters in the Unicode was a zero-extended UTF-16.