Compositor end-delay sampler (content_shell screenshots)

#41428771 Filed 2018-11-28 Status: New P4

Bug summary

This sampler demonstrates how endDelay should affect compositor animation timing. The issue tracks missing compositor-side support for end delay in Chromium animation sampling.

Deterministic sampler

Two transform animations with identical keyframes and timing.
A: endDelay = 0ms.
B: endDelay = -2000ms (active interval ends earlier).
Both are paused and sampled at fixed currentTime values.

Sample at 1500ms

A: endDelay 0ms

B: endDelay -2000ms

Sample at 3200ms

A: endDelay 0ms

B: endDelay -2000ms

Sample at 4500ms

A: endDelay 0ms

B: endDelay -2000ms

content_shell screenshots

content_shell capture at 1500ms — 1500ms: both animations are still in active phase.

content_shell capture at 3200ms — 3200ms: B has already reached forwards fill due to negative endDelay.

content_shell capture at 4500ms — 4500ms: A is still active, B remains at the filled endpoint.

Capture command

DISPLAY=:21 python3 capture_content_shell_screenshots.py