
In our vsync waiter and related tests, we hardcode the "CADisableMinimumFrameDurationOnPhone" key in several places. This pulls those into a constant kCADisableMinimumFrameDurationOnPhoneKey declared in the vsync waiter header, which is non-public, and uses that instead. [C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style