Bug 1522407 is going to address test_animation_performance_warning.html failure. It addressed test failure, but WebRenderBridgeParent still hit NS_ERROR.

https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=223987095&repo=try&lineNumber=141628

Error message was "ASSERTION: Tried to delete invalid animation".
https://searchfox.org/mozilla-central/rev/88324fa347928412cb3e4c92418311b7ef5b4271/gfx/layers/wr/WebRenderBridgeParent.cpp#497

(In reply to Sotaro Ikeda [:sotaro] from comment #0)

Error message was "ASSERTION: Tried to delete invalid animation".

WebRenderBridgeParent::RemoveEpochDataPriorTo() has a problem. Animation was deleted too early in the following STR.

-[1] Request to delete an animation A by WebRenderBridgeParent::RecvDeleteCompositorAnimations()
-[2] Request to re-add the animation A by WebRenderParentCommand::TOpAddCompositorAnimations message
-[3] WebRenderBridgeParent::RemoveEpochDataPriorTo() deletes obsoleted animation

In the STR, [3] removed animation A even when [2] re-added animation A again. It should not be deleted.

By comment 1, there could be a case that Animation does not run depends on a timing.

Confirmed that attachment 9039478 [details] address the ASSERTION in comment 0.
https://treeherder.mozilla.org/#/jobs?repo=try&revision=4554d10890d7633a5cb66e9796c561ead8b9a255

https://treeherder.mozilla.org/#/jobs?repo=try&revision=d8039d3cd86ca9e0cf97963545ec16c3b2aab770

https://hg.mozilla.org/mozilla-central/rev/a1f4d0d6d971