GitLab

When there are multiple requests for setting photo options callbacks,
pushing the callbacks into a queue instead of storing the latest one only.

Bug: 1142931
Test: https://1142931.glitch.me/?timeout=100
Change-Id: Ia4feac88de5600b696cf05f31fd0cea7c2612223
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2513809Reviewed-by: Shik Chen <shik@chromium.org>
Commit-Queue: Wei Lee <wtlee@chromium.org>
Auto-Submit: Wei Lee <wtlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823937}