Move another bunch of extension API tests to manifest_version 2.

chrome/test/data/extensions/api_test/content_scripts/all_frames/manifest.json

 {
   "name": "content_script_all_frames",
   "version": "1.0",
+  "manifest_version": 2,
   "description": "Tests the all_frames property of content script declarations.",
   "background_page": "test.html",
   "permissions": ["tabs"],
   "content_scripts": [
     {
       "matches": ["http://*/*"],
       "js": ["top_frame_only.js"]
     },
     {
       "matches": ["http://*/*"],
       "js": ["all_frames.js"],
       "all_frames": true
     }
   ]
 }