commit e3a5475734d0ecad8043f4347f505dfa0659e477
author Joe Mason <joenotcharles@google.com> Fri Apr 25 00:24:50 2025
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Apr 25 00:24:50 2025
tree 563271eeb3f1610280d54fcb851f6ef9a13dc5ca
parent 218639bd8d3fa9500017ca0bdcfe274ee2182ce9

Make TabStatsTracker browser test less fragile

When TabStatsTracker is enabled on Android, a lot of these tests fail
because they can't deal with minor timing changes. This updates the
tests to be more consistent:

* Adds ASSERTs that objects aren't null, so that if they're ever null
  on a new platform the test will fail instead of crashing.
* Updates existing CHECKs to ASSERTs.
* Removes observers at the end of all tests, so that if a new platform
  sends notifications during teardown they won't crash.
* Uses specific matchers in expectations instead of `_`, which can
  cause confusing messages when there are unexpected notifications.
* Adds explicit expectations of tab visibility, to give more context
  around unexpected OnTabVisibilityChanged notifications.
* Wait for the PrerenderHostObserver to observe an async prerender
  activation, to avoid races on platforms with different timings.
* Use content::WaiterHelper in AudioStartObserver, which correctly
  handles the race if tabs are made audible before the test starts
  waiting.

Bug: 412634171
Change-Id: Ibe554ce0606fa4f8e0c065ab605fefb5c0e41a79
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6485366
Commit-Queue: Patrick Monette <pmonette@chromium.org>
Auto-Submit: Joe Mason <joenotcharles@google.com>
Reviewed-by: Patrick Monette <pmonette@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1451554}