Add more string_util functions to base namespace.

ui/base/webui/jstemplate_builder.cc

Index: ui/base/webui/jstemplate_builder.cc
diff --git a/ui/base/webui/jstemplate_builder.cc b/ui/base/webui/jstemplate_builder.cc
index 2aa80a39889b6e5ac39b39bff127a0a604e088c5..3e9d4110ce9f82624a2cae4e9f9d3214eecd8cd5 100644
--- a/ui/base/webui/jstemplate_builder.cc
+++ b/ui/base/webui/jstemplate_builder.cc
@@ -27,7 +27,7 @@ void AppendJsonHtml(const base::DictionaryValue* json, std::string* output) {
 
   // </ confuses the HTML parser because it could be a </script> tag.  So we
   // replace </ with <\/.  The extra \ will be ignored by the JS engine.
-  ReplaceSubstringsAfterOffset(&javascript_string, 0, "</", "<\\/");
+  base::ReplaceSubstringsAfterOffset(&javascript_string, 0, "</", "<\\/");
 
   output->append("<script>");
   output->append(javascript_string);