GitLab

There are cases where we may get multiple canplaythrough events, we
need to ensure that ones beyond the first don't trigger crashes.

Bug: 1064635
Change-Id: I93ab49a5060e2dbbb39791e2e2193d47b6dd3959
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2119643
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#753447}