Convert ReplaceStringPlaceholders(std::string...) to take a

base/string_util.cc

Index: base/string_util.cc
diff --git a/base/string_util.cc b/base/string_util.cc
index b0ab3a6b7400026f49b24f299ea5fff5dcfc3db1..a62b905227ec58c7474629243bb9744309958074 100644
--- a/base/string_util.cc
+++ b/base/string_util.cc
@@ -1423,25 +1423,23 @@ void SplitStringAlongWhitespace(const std::string& str,
   SplitStringAlongWhitespaceT(str, result);
 }
 
-template<class StringType>
-StringType DoReplaceStringPlaceholders(const StringType& format_string,
-                                       const std::vector<StringType>& subst,
-                                       std::vector<size_t>* offsets) {
+template<class FormatStringType, class OutStringType>
+OutStringType DoReplaceStringPlaceholders(const FormatStringType& format_string,
+    const std::vector<OutStringType>& subst, std::vector<size_t>* offsets) {
   int substitutions = subst.size();
   DCHECK(substitutions < 10);
 
   int sub_length = 0;
-  for (typename std::vector<StringType>::const_iterator iter = subst.begin();
-       iter != subst.end();
-       ++iter) {
+  for (typename std::vector<OutStringType>::const_iterator iter = subst.begin();
+       iter != subst.end(); ++iter) {
     sub_length += (*iter).length();
   }
 
-  StringType formatted;
+  OutStringType formatted;
   formatted.reserve(format_string.length() + sub_length);
 
   std::vector<ReplacementOffset> r_offsets;
-  for (typename StringType::const_iterator i = format_string.begin();
+  for (typename FormatStringType::const_iterator i = format_string.begin();
        i != format_string.end(); ++i) {
     if ('$' == *i) {
       if (i + 1 != format_string.end()) {
@@ -1482,7 +1480,7 @@ string16 ReplaceStringPlaceholders(const string16& format_string,
   return DoReplaceStringPlaceholders(format_string, subst, offsets);
 }
 
-std::string ReplaceStringPlaceholders(const std::string& format_string,
+std::string ReplaceStringPlaceholders(const base::StringPiece& format_string,
                                       const std::vector<std::string>& subst,
                                       std::vector<size_t>* offsets) {
   return DoReplaceStringPlaceholders(format_string, subst, offsets);