This CL makes it possible to build sky_shell on Linux. It doesn't do much, but
it doesn't crash on startup. The goal is to evetually be able to test sky_shell
on the bots and to be able to run the test_sky on Mac.
R=eseidel@chromium.org
Review URL: https://codereview.chromium.org/1202323002.
This CL plumbs resize notifications from SkyView to Engine. I've taken the
opportunity to reorganize how notifications generated by SkyView are plumbed to
the GPU and UI threads. This approach should reduce the amount of plumbing
needed for new notifications.
R=eseidel@chromium.org
Review URL: https://codereview.chromium.org/880443003
