Keep event page alive when there's some Pepper plugin on it.

ppapi/tests/extensions/load_unload/manifest.json

 {
-  "name": "Extensions Button",
-  "description": "Access the Extensions window directly from the toolbar",
-  "version": "1",
+  "name": "Lazy background wait for NaCl test",
+  "description": "Tests that a lazy background page stays alive while a NaCl module exists in its DOM",
+  "version": "0",
   "manifest_version": 2,
-  "permissions": ["tabs"],
   "background": {
     "scripts": ["background.js"],
     "persistent": false
   },
   "browser_action": {
     "default_icon" : "ext_icon.png",
     "default_title": "Open Extensions window"
   }
 }