This makes the entry points a bit smaller and avoids redundant return
statements.

BUG=angleproject:1309

Change-Id: I895c26d4235900578f5acc0eb94a7deef67b946b
Reviewed-on: https://chromium-review.googlesource.com/483428
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>