tree e2f88a45a653deeb45995c6020460e4db6aad639
parent fcb671ed8b068b25cee87429d803833777f35c2c
author Xida Chen <xidachen@chromium.org> 1623366146 -0700
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> 1623366991 -0700

[composite-bgcolor-animation] Null check on GetBackgroundColorPaintImageGenerator

When calling GetBackgroundColorPaintImageGenerator on local_root,
we should always performa a null-check for local_root because the
it could have been detached.

This CL does the null-check. A test case is added, exactly the case
when the local_root is detached. There is no crash with the fix.

Bug: 1215879
Change-Id: Id2401dae593da9ee960e5e5336c4d4876eb39f79
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2951382
Commit-Queue: Xida Chen <xidachen@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#891421}