GitLab

Broke LongScreenshotsEntry into entry logic and bitmap generation logic
for a cleaner separation. Also added logic to propagate errors.

Bug: 1153969
Change-Id: Ie81a7ab8fc8c368f11127d219b37101d62ee61f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2622055Reviewed-by: Kyle Milka <kmilka@chromium.org>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Mehran Mahmoudi <mahmoudi@chromium.org>
Commit-Queue: Tanya Gupta <tgupta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843608}