chore(bidi): disable thottling of background tabs in Firefox

[whimboo]

With this patch throttling of background tabs will no longer happen. This PR changes the following:

• No throttling of the timer to 1s as minimum
• No throttling of rendering (requestAnimationFrame) by a newly added preference in Firefox Nightly.

@yury-s at least one test is no longer timing out with Firefox. I'm not sure if others might benefit from that as well. Also depending on your usage of setTimeout in general you should see a big improvement.

[github-actions]

Test results for "tests 1"

9 flaky

⚠️ [firefox-page] › tests/page/page-evaluate.spec.ts:403:3 › should throw for too deep reference chain @firefox-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/browsercontext-clearcookies.spec.ts:92:3 › should remove cookies by domain @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/debug-controller.spec.ts:261:1 › should highlight inside iframe @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/proxy.spec.ts:93:11 › should proxy local network requests › by default › loopback address @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/proxy.spec.ts:93:11 › should proxy local network requests › by default › link-local @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/selector-generator.spec.ts:116:5 › selector generator › should escape text with slash @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/trace-viewer.spec.ts:169:1 › should show action context on locators and other common actions @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/trace-viewer.spec.ts:1719:1 › should toggle canvas rendering @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-set-input-files.spec.ts:205:3 › should upload multiple large files @webkit-ubuntu-22.04-node18

37588 passed, 648 skipped
✔️✔️✔️

Merge workflow run.

[yury-s]

Nice! It looks like we don't use this preferences with juggler (see https://github.com/microsoft/playwright/tree/main/browser_patches/firefox/preferences), which means there is probably another preference that helps us avoid the throttling. I'll try to incorporate this settings to our other builds too and see if it makes a difference.

Update: I just noticed from your description that at lease 'layout.testing.top-level-always-active' was added a few days ago, no wonder we don't have it yet.

[yury-s]

It's another reason to have a canonical set of preferences that should be used for testing in Firefox.

[whimboo]

Nice! It looks like we don't use this preferences with juggler (see https://github.com/microsoft/playwright/tree/main/browser_patches/firefox/preferences), which means there is probably another preference that helps us avoid the throttling. I'll try to incorporate this settings to our other builds too and see if it makes a difference.

Yes, you probably want to add this preference there as well.

Update: I just noticed from your description that at lease 'layout.testing.top-level-always-active' was added a few days ago, no wonder we don't have it yet.

Correct. After investigation of the raf test case in your repository I noticed that this was a problem and requested a possibility to turn throttling of for rendering. Is there a way to see how this affects the non BiDi-tests for Firefox? Do you have some general performance numbers recorded to detect perf changes?

It's another reason to have a canonical set of preferences that should be used for testing in Firefox.

The preferences as used in this PR are not going to become default preferences when Marionette or WebDriver BiDi is active in Firefox. Our aim is to run as close as possible to the users settings, and running tests in parallel is usually not such a thing, but could be requested by the user. Maybe it could be some kind of configuration option.