Fix app_list_unittests
* Fixes app_list_unittests dependencies
* Adds app_list_model_unittest (adds simple observer tests)

BUG=none

Review URL: https://codereview.chromium.org/38133002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230865 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230865