Ignore non-active fullscreen windows for shelf state.
BUG=319889
TEST=ShelfLayoutManagerTest.FullscreenWindowInFrontHidesShelf, ShelfLayoutManagerTest.FullscreenWindowOnSecondDisplay,WorkspaceLayoutManagerTest.NotifyFullscreenChanges
TEST=Navigate to a site using HTML5 fullscreen API, alt tab away to another window and back. Window remains fullscreen but shelf shows while another window is in front.
Review URL: https://codereview.chromium.org/
100903002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239859 0039d316-1c4b-4281-b951-d872f2087c98