(Trying to finish FastAccessorAssembler this week. This should make it easier to pick up the Blink side of this work later on.)

BUG=chromium:508898
SOUNDTRACK=http://youtu.be/i1EG-MKy4so
LOG=Y

Review URL: https://codereview.chromium.org/1620293002

Cr-Commit-Position: refs/heads/master@{#33671}