[Temp] Ozone fixes for shared_library builds.

As part of the effort to support running Crosswalk with Wayland, this patch
set introduces some temporary commits to aid building with
-Dcomponent=shared_library.

One of them is already upstream and will not be necessary anymore once we
switch to a more recent Chromium milestone, whereas the other may be
necessary for a little longer but is being maintained by the Ozone-Wayland
team.