Refactor the various ways to control what users can do to extensions.

chrome/browser/ui/views/ash/app_list/extension_app_item.cc

Index: chrome/browser/ui/views/ash/app_list/extension_app_item.cc
===================================================================
--- chrome/browser/ui/views/ash/app_list/extension_app_item.cc	(revision 138227)
+++ chrome/browser/ui/views/ash/app_list/extension_app_item.cc	(working copy)
@@ -7,6 +7,7 @@
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/extension_uninstall_dialog.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ -222,7 +223,9 @@
         !extension->options_url().is_empty();
   } else if (command_id == UNINSTALL) {
     const Extension* extension = GetExtension();
-    return extension && Extension::UserMayDisable(extension->location());
+    return extension &&
+           ExtensionSystem::Get(profile_)->management_policy()
+             ->UserMayModifyStatus(extension, NULL);
   }
   return true;
 }