Gardening: Update to latest revision.
Gardening: Adopt to https://codereview.chromium.org/312393002/
Gardening: Adopt to https://codereview.chromium.org/341253002/
Delete OzoneChannelHostFactory.

OzoneChannelHostFactory is not used anymore. This CL removes this
class.
Move everything under content to ui namespace.
Move everything related to events from content to ui/events.
Move everything under content/ to ui/public
Fix coding style.
Media: Fix shared component build.
Temporarily disable HWA decoding support.

Issue: https://github.com/01org/ozone-wayland/issues/240