GitLab

This registers accelerator table entries for VKEY_BROWSER_(BACK|FORWARD)
to IDC_(BACK|FORWARD) for linux platforms (linux desktop and ChromeOS) so
that hardward back/forward keys navigate the browser.

BUG=338945

Review URL: https://codereview.chromium.org/149273002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247853 0039d316-1c4b-4281-b951-d872f2087c98