GitLab

- Call resetString() after setting the textbox value, so that future
  updates to the textbox will trigger an input-change event.
- Also make some conditions more clear in the margins code.

Bug: 1046683
Change-Id: I742f264a0dca2c1b5a41e769ada5f5d2966e5c92
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2032433
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737207}