Blink side changes for adding Writing direction to the context menu for linux gtk

Chromium side CL is here https://codereview.chromium.org/73963004/

BUG=91178

Review URL: https://codereview.chromium.org/66313007

git-svn-id: svn://svn.chromium.org/blink/trunk@162341 bbb929c8-8fbe-4397-9dbb-9b2b20218538