Move another bunch of extension API tests to manifest_version 2.

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

 {
   "name": "content_script_extension_process",
   "version": "1.0",
+  "manifest_version": 2,
   "description": "Content scripts should get injected into web pages, even when the webpages are in an extension process.",
   "background_page": "background.html",
   "content_scripts": [
     {
       "matches": ["http://*/*"],
       "js": ["injectionator.js"],
       "all_frames": true
     }
   ]
 }