Add first-class support for user scripts

chrome/common/extensions/extension_error_utils.cc

Index: chrome/common/extensions/extension_error_utils.cc
diff --git a/chrome/common/extensions/extension_error_utils.cc b/chrome/common/extensions/extension_error_utils.cc
index 724cdcd78e5e8d24a910e31156899404b21dd697..0256c8d8e634a8ab80c5faac481e016de4485866 100644
--- a/chrome/common/extensions/extension_error_utils.cc
+++ b/chrome/common/extensions/extension_error_utils.cc
@@ -8,7 +8,7 @@
 
 std::string ExtensionErrorUtils::FormatErrorMessage(
     const std::string& format,
-    const std::string s1) {
+    const std::string& s1) {
   std::string ret_val = format;
   ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
   return ret_val;
@@ -16,10 +16,22 @@ std::string ExtensionErrorUtils::FormatErrorMessage(
 
 std::string ExtensionErrorUtils::FormatErrorMessage(
     const std::string& format,
-    const std::string s1,
-    const std::string s2) {
+    const std::string& s1,
+    const std::string& s2) {
   std::string ret_val = format;
   ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
   ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s2);
   return ret_val;
 }
+
+std::string ExtensionErrorUtils::FormatErrorMessage(
+    const std::string& format,
+    const std::string& s1,
+    const std::string& s2,
+    const std::string& s3) {
+  std::string ret_val = format;
+  ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
+  ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s2);
+  ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s3);
+  return ret_val;
+}