linux aura: Restore ctrl+shift+page-up/down to move tab left/right behaviour.

BUG=318873
R=sky@chromium.org

Review URL: https://codereview.chromium.org/76043002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236001 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236001