[Ozone-Drm] Scan for displays on browser size during startup
During startup, Chrome expects synchronous display configuration, so we
need to present the list of displays before we get a chance to connect
to the GPU process. This patch will populate a list of dummy displays on
startup and the platform will pretend it can configure them until the
connection to the GPU process is established.
BUG=484294
Review URL: https://codereview.chromium.org/
1131813003
Cr-Commit-Position: refs/heads/master@{#329786}