Add more string_util functions to base namespace.

extensions/common/error_utils.cc

Index: extensions/common/error_utils.cc
diff --git a/extensions/common/error_utils.cc b/extensions/common/error_utils.cc
index 2343c04bf7edfb0f122dd756e46cf33f726be63a..14ca2a96c2f8aca36f5885c7e27845bbf4aa8aca 100644
--- a/extensions/common/error_utils.cc
+++ b/extensions/common/error_utils.cc
@@ -12,7 +12,7 @@ namespace extensions {
 std::string ErrorUtils::FormatErrorMessage(const std::string& format,
                                            const std::string& s1) {
   std::string ret_val = format;
-  ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
+  base::ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
   return ret_val;
 }
 
@@ -20,8 +20,8 @@ std::string ErrorUtils::FormatErrorMessage(const std::string& format,
                                            const std::string& s1,
                                            const std::string& s2) {
   std::string ret_val = format;
-  ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
-  ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s2);
+  base::ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
+  base::ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s2);
   return ret_val;
 }
 
@@ -30,9 +30,9 @@ std::string ErrorUtils::FormatErrorMessage(const std::string& format,
                                            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);
+  base::ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s1);
+  base::ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s2);
+  base::ReplaceFirstSubstringAfterOffset(&ret_val, 0, "*", s3);
   return ret_val;
 }