Update rendering helper to use async swap buffers

Update rendering helper to use async swap buffers

This change is one step closer to deprecating the blocking swap buffers
call.

Note, platforms that support blocking swap buffers are still supported
through the async API by immediately calling the callback. In the case
of the VDA unittests, nothing changes since scheduling the next frame
happens in the callback (after swap buffers finishes).

TEST=Ran VDA unittests on Link
BUG=none

Review URL: https://codereview.chromium.org/1154813003

Cr-Commit-Position: refs/heads/master@{#332605}