Update code that previously constructed strings from string iterators only to...

chrome/common/extensions/extension.cc

Index: chrome/common/extensions/extension.cc
===================================================================
--- chrome/common/extensions/extension.cc	(revision 63369)
+++ chrome/common/extensions/extension.cc	(working copy)
@@ -64,7 +64,7 @@
 static void ConvertHexadecimalToIDAlphabet(std::string* id) {
   for (size_t i = 0; i < id->size(); ++i) {
     int val;
-    if (base::HexStringToInt(id->substr(i, 1), &val))
+    if (base::HexStringToInt(id->begin() + i, id->begin() + i + 1, &val))
       (*id)[i] = val + 'a';
     else
       (*id)[i] = 'a';