Revert 113071 - Revert 113047 - Make ExtensionService use ExtensionSet.

chrome/browser/extensions/user_script_listener.cc

Index: chrome/browser/extensions/user_script_listener.cc
===================================================================
--- chrome/browser/extensions/user_script_listener.cc	(revision 113231)
+++ chrome/browser/extensions/user_script_listener.cc	(working copy)
@@ -200,7 +200,7 @@
       // Clear all our patterns and reregister all the still-loaded extensions.
       URLPatterns new_patterns;
       ExtensionService* service = profile->GetExtensionService();
-      for (ExtensionList::const_iterator it = service->extensions()->begin();
+      for (ExtensionSet::const_iterator it = service->extensions()->begin();
            it != service->extensions()->end(); ++it) {
         if (*it != unloaded_extension)
           CollectURLPatterns(*it, &new_patterns);