Feature description:

The saveData attibute is a boolean in the Network Information API that indicates a client’s explicit opt-in for reduced data usage, due to high transfer costs, slow connection speeds, or other reasons. It's use allows JavaScript to make decisions that result in reduced data use, such as to load smaller images and video resources, or reduce buffering or predictive actions.

Eng owner: bengr@chromium.org, tbansal@chromium.org
Product owner: aposner@chromium.org

Explainer: https://github.com/WICG/netinfo/issues/42
Spec: https://wicg.github.io/netinfo/#-dfn-savedata-dfn-attribute

Metrics:
We will monitor per-page data use (in PLM UMA, and DataUse.BytesReceived*) against a Data Saver holdback Finch group, will look at API counters to measure popularity of the feature, and will look at UI actions to disable Data Saver as a negative signal.