SupportsUserData and manifest handlers for Extension; use them for the Omnibox API.
Note that manifest handlers aren't available in the renderer (there seems to be no place to register them). At least for Omnibox, the renderer doesn't need to parse the manifest field, but this won't be true everywhere.
Pull a bunch of Omnibox API stuff out of ExtensionService.
BUG=159265
Review URL: https://chromiumcodereview.appspot.com/11446034
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@172638 0039d316-1c4b-4281-b951-d872f2087c98
27 files changed
