Report Critical-CH caused restart in NavigationTiming

[arichiv]

Request for position on an emerging web specification

Information about the spec

• Spec Title: Report Critical-CH caused restart in NavigationTiming
• Spec URL: Add criticalCHRestart w3c/navigation-timing#188
• GitHub repository: https://github.com/w3c/navigation-timing/

Design reviews and vendor positions

• TAG Design Review: [FYI] Report Critical-CH caused restart in NavigationTiming w3ctag/design-reviews#833
• Mozilla standards-positions issue: Report Critical-CH caused restart in NavigationTiming mozilla/standards-positions#767
• Chromium Intent to Ship: https://groups.google.com/a/chromium.org/g/blink-dev/c/f28WWMD8HVE

Bugs tracking this feature

• Chromium Feature: https://chromestatus.com/feature/5140317616996352
• Chromium Issue: https://crbug.com/1425910

Anything else we need to know

Websites can indicate that a particular Client Hint is critical to the page by including it in a Critical-CH HTTP response header. Doing so will trigger a connection restart if the hint listed in the Critical-CH HTTP response header could be (but wasn’t) included in the HTTP request initially sent. We should indicate this has happened in Navigation Timing so that developers can know if a restart occurred and impacted timing.

[hober]

We need to come to a position on #20 before we can come to positions on proposals that use the Client Hints infrastructure.