Linux: Reorder browser list on workspace switch

Opening a link from a 3rd party app picks the most recently
used profile/browser to open the new tab in.  Whenever a user
changes workspaces, reorder the browser list such that the
browsers in the current workspace are moved to the top of the
list.  This way, when a user opens a link, it will open in a
browser on the current workspace (if there are any browsers).

BUG=619673

Review-Url: https://codereview.chromium.org/2108933003
Cr-Commit-Position: refs/heads/master@{#404544}
12 files changed