Bag of scheduling tweaks

 Bug: 15118640

 * Prevent over-stuffing the queue by dropping frames
 * Prevent double-drawing in one pulse by RT by deferring
   vsync registration until post-draw so that it catches
   the next vsync pulse instead of the current one
 * Bias vsync race condition towards the UI thread
 * Fix queueDelay to actually work

Change-Id: Ibf584258bd93ebcbba058bd976dc8b307f1c6155