WPT details: WebGPU/WGSL have a conformance test suite (https://github.com/gpuweb/cts) that is regularly pulled into Chromium and part of the testing of Dawn/Tint in Chromium.
WebGPU timestamp queries allow WebGPU applications to measure precisely (down to the nanosecond) how much time their GPU commands take to execute, especially at the beginning and end of passes. Timestamp queries are heavily used to gain insights into the performance and behavior of GPU workloads. While the WebGPU specification makes timestamp queries an optional feature due to timing attack concerns, we believe that timestamp queries quantization provides a good middle ground by reducing the precision of timers with a resolution of 100 microseconds.