chrome: Add support for use_glib=true to wayland server.

This adds a GLib WaylandWatcher implemenatation that allows the
Wayland server to listen for and dispatch messages when using a
GLib message loop.

BUG=549781
TEST=build chrome without use_glib=false and run with --enable-wayland-server

Review URL: https://codereview.chromium.org/1486623003

Cr-Commit-Position: refs/heads/master@{#362719}
3 files changed