This allows us remove the duplicated code in the various typed
methods that checks for an error before committing.

BUG=angle:729

Change-Id: Icd0ad2be55ac423baec3855e05c53f4b624b6764
Reviewed-on: https://chromium-review.googlesource.com/220275Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>