62129447cd
This is done for both Android and regular builds, and it brings a nice
1% perf improvement on Windows, and 2% on Android.
Do not get rid of Speedometer2 yet, adding Speedometer3 already brings
an interesting performance boost.
To update to the latest version run
> ./mach vendor third_party/webkit/PerformanceTests/Speedometer3/moz.yaml
Differential Revision: https://phabricator.services.mozilla.com/D194040