Add more string_util functions 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 c41da98c17d1846539aaeeca077bca0a2c536a6d..b6d668d952036c3fb0ec99e52d8310c1f457bb57 100644
--- a/net/base/filename_util.cc
+++ b/net/base/filename_util.cc
@@ -36,21 +36,21 @@ GURL FilePathToFileURL(const base::FilePath& path) {
 
   // must be the first substitution since others will introduce percents as the
   // escape character
-  ReplaceSubstringsAfterOffset(
+  base::ReplaceSubstringsAfterOffset(
       &url_string, 0, FILE_PATH_LITERAL("%"), FILE_PATH_LITERAL("%25"));
 
   // semicolon is supposed to be some kind of separator according to RFC 2396
-  ReplaceSubstringsAfterOffset(
+  base::ReplaceSubstringsAfterOffset(
       &url_string, 0, FILE_PATH_LITERAL(";"), FILE_PATH_LITERAL("%3B"));
 
-  ReplaceSubstringsAfterOffset(
+  base::ReplaceSubstringsAfterOffset(
       &url_string, 0, FILE_PATH_LITERAL("#"), FILE_PATH_LITERAL("%23"));
 
-  ReplaceSubstringsAfterOffset(
+  base::ReplaceSubstringsAfterOffset(
       &url_string, 0, FILE_PATH_LITERAL("?"), FILE_PATH_LITERAL("%3F"));
 
 #if defined(OS_POSIX)
-  ReplaceSubstringsAfterOffset(
+  base::ReplaceSubstringsAfterOffset(
       &url_string, 0, FILE_PATH_LITERAL("\\"), FILE_PATH_LITERAL("%5C"));
 #endif
 
@@ -121,7 +121,7 @@ bool FileURLToFilePath(const GURL& url, base::FilePath* file_path) {
   std::string new_path;
   do {
     new_path = path;
-    ReplaceSubstringsAfterOffset(&new_path, 0, "//", "/");
+    base::ReplaceSubstringsAfterOffset(&new_path, 0, "//", "/");
     path.swap(new_path);
   } while (new_path != path);