Looking at this query the most common renderer strings matching "nvidia" are NVIDIA Tegra and NVIDIA Tegra 3. Then there are a few individual users that look like emulators running on desktop nvidia. eg Android Emulator OpenGL ES Translator (NVIDIA GeFo.

So let's enable when the renderer string contains NVIDIA Tegra for now.

https://hg.mozilla.org/mozilla-central/rev/1807c0aa9121

Comment on attachment 9227652 [details]
Bug 1716971 - Enable webrender on Android on NVIDIA Tegra GPUs. r?jrmuizel

Beta/Release Uplift Approval Request

• User impact if declined: We have such a low number of users running on this GPU on Nightly and Beta that there is no benefit to waiting a full cycle. ~100 on nightly and ~300 on beta, compared to ~10000 on release. Even if this were to cause a completely unusable browser on these GPUs, we would not receive a bug report until it hits release, so waiting will just make us slower to find bugs.
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Medium
• Why is the change risky/not risky? (and alternatives if risky): Low number of affected users
• String changes made/needed:

I got the GPU usage numbers from here (modifying the query source for beta and nightly)

Comment on attachment 9227652 [details]
Bug 1716971 - Enable webrender on Android on NVIDIA Tegra GPUs. r?jrmuizel

approved for fenix 90.0.0-beta.5

https://hg.mozilla.org/releases/mozilla-beta/rev/29c702c10dd3