Update ToLower/UpperASCII API

base/strings/string_util.cc

Index: base/strings/string_util.cc
diff --git a/base/strings/string_util.cc b/base/strings/string_util.cc
index 725d86da8ac7c64693f566c0fdb7b9cd23968b44..4b5b7a6b35c0b9e11ab4c9899949f4cce9374af5 100644
--- a/base/strings/string_util.cc
+++ b/base/strings/string_util.cc
@@ -148,6 +148,40 @@ bool IsWprintfFormatPortable(const wchar_t* format) {
   return true;
 }
 
+template<typename StringType>
+StringType ToLowerASCIIT(BasicStringPiece<StringType> str) {
+  StringType ret;
+  ret.reserve(str.size());
+  for (size_t i = 0; i < str.size(); i++)
+    ret.push_back(ToLowerASCII(str[i]));
+  return ret;
+}
+
+std::string ToLowerASCII(StringPiece str) {
+  return ToLowerASCIIT<std::string>(str);
+}
+
+string16 ToLowerASCII(StringPiece16 str) {
+  return ToLowerASCIIT<string16>(str);
+}
+
+template<typename StringType>
+StringType ToUpperASCIIT(BasicStringPiece<StringType> str) {
+  StringType ret;
+  ret.reserve(str.size());
+  for (size_t i = 0; i < str.size(); i++)
+    ret.push_back(ToUpperASCII(str[i]));
+  return ret;
+}
+
+std::string ToUpperASCII(StringPiece str) {
+  return ToUpperASCIIT<std::string>(str);
+}
+
+string16 ToUpperASCII(StringPiece16 str) {
+  return ToUpperASCIIT<string16>(str);
+}
+
 template<class StringType>
 int CompareCaseInsensitiveASCIIT(BasicStringPiece<StringType> a,
                                  BasicStringPiece<StringType> b) {