GitLab

Made ServiceWorkerPaymentAppFactory singleton.

Bug: 786116
Change-Id: I263edd64e7452a81f07011f1a7bda83e8b57c90e
Reviewed-on: https://chromium-review.googlesource.com/774906Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Commit-Queue: Ganggui Tang <gogerald@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518442}