Revert 232020 "Add a fast_chrome_app_list_unittests target."

> Add a fast_chrome_app_list_unittests target.
> 
> This requires making AppListShower use BrowserContext instead
> of Profile, and splitting out a new app_list target out of
> browser_ui that the new unit test target can depend on.
> 
> BUG=310376
> 
> Review URL: https://codereview.chromium.org/43043002

TBR=koz@chromium.org

Review URL: https://codereview.chromium.org/54333007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232211 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232211