BraveRewardsBrowserTest.* tests frequently time out

[bbondy]

Brave Rewards tests are frequently timing out which causes each PR to take longer and also takes longer for people checking tests locally on their tasks.

As an example:

BraveRewardsBrowserTest.ProcessPendingContributions (TIMED OUT)

But there are others too (8) that frequently timeout.

cc @NejcZdovc

Here are some ideas for cleaning up tests:

• Add a method to enable Rewards without using the Rewards Page UI, and switch tests to it where possible. (Need a way for tests to enable Rewards without UI #7002)
• Replace use of sleep/polling with a MutationObserver that will watch for the page to be modified. (Replace use of timed delays in browser tests to reduce flakiness #7060)
• Switch tests to use TipViaCode where possible. (Switch to TipViaCode when possible #7184)
• Add a method to claim an initial grant without going through the Rewards Page or Rewards Panel UI, and switch tests to using it where possible. (Browser tests: Claim via code #9129)
• Add a method to open the Site Banner without going through the Rewards Panel, and switch tests to using it where possible.
• Move utility functions into a separate file.
• Split Rewards Service tests into multiple files based on test category. (Split rewards browser tests in separate categories #9204)

[bsclifton]

@NejcZdovc is this still a problem? Or can we close this out

[NejcZdovc]

@bsclifton this is an epic. We still have couple of them to complete, before we can close this one.

[kjozwiak]

Just a heads up, created #9339. Looks like BraveRewardsBrowserTest.NotVerifiedWallet has been failing intermittently here and there. I'm not sure if this work will fix that issue but figured I would mention it here.

[kjozwiak]

Just an update, still seeing the following failure from time to time:

03:29:38  [  FAILED  ] BraveRewardsBrowserTest.ProcessPendingContributions, where TypeParam =  and GetParam() =  (37759 ms)
03:29:38  [539/540] BraveRewardsBrowserTest.ProcessPendingContributions (38025 ms)
03:29:44  [540/540] BraveRewardsBrowserTest.SplitProcessorAutoContribution (5241 ms)
03:29:44  1 test failed:
03:29:44      BraveRewardsBrowserTest.ProcessPendingContributions (../../brave/components/brave_rewards/browser/rewards_service_browsertest.cc:2186)

[NejcZdovc]

@kjozwiak This was fixed here #9687, so probably just not running the latest code

[bsclifton]

@NejcZdovc should we close this issue out?
There's a similar one open with #9339

[NejcZdovc]

closing as nothing new is planned for this and browser tests are stable now