Remove Extension's accessors for ExtensionActions.

extension->browser_action() is replaced by ExtensionActionManager::Get(profile)->GetBrowserAction(*extension), and similar for page actions and script badges.

This is the second step of a four-part refactoring to simplify icon handling.
The subsequent parts are: 
3) Move ExtensionAction from common/ to browser/ 
4) Make the icon-loading and -caching classes into ExtensionAction methods. 

BUG=153463

Review URL: https://chromiumcodereview.appspot.com/11036025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@161654 0039d316-1c4b-4281-b951-d872f2087c98
46 files changed