Create Common::ToLower and Common::ToUpper

Source/Core/Common/StringUtil.cpp

@@ -669,3 +669,16 @@ std::string GetEscapedHtml(std::string html)
   }
   return html;
 }
+
+namespace Common
+{
+void ToLower(std::string* str)
+{
+  std::transform(str->begin(), str->end(), str->begin(), [](char c) { return Common::ToLower(c); });
+}
+
+void ToUpper(std::string* str)
+{
+  std::transform(str->begin(), str->end(), str->begin(), [](char c) { return Common::ToUpper(c); });
+}
+}  // namespace Common

Source/Core/Common/StringUtil.h

@@ -240,3 +240,17 @@ std::vector<std::string> CommandLineToUtf8Argv(const wchar_t* command_line);
 #endif
 
 std::string GetEscapedHtml(std::string html);
+
+namespace Common
+{
+inline char ToLower(char ch)
+{
+  return std::tolower(ch, std::locale::classic());
+}
+inline char ToUpper(char ch)
+{
+  return std::toupper(ch, std::locale::classic());
+}
+void ToLower(std::string* str);
+void ToUpper(std::string* str);
+}  // namespace Common