Chrome Version: 73.0.3642.0/dev
OS: MacOs

What steps will reproduce the problem?
(1) Open the attached testcase
(2) Scroll up and down
(3) Notice the green box gets clipped

What is the expected result?
The green box should not scroll and should not be clipped.

What happens instead?
The green box scrolls.

This is a regression from:
[Blink] Avoid SetShouldFlattenTransform() back and forth
https://chromium-review.googlesource.com/c/chromium/src/+/780803/
This patch stopped aggressively invalidating layers which probably exposed the real underlying bug.

This seems to be fixed by --enable-blink-features=BlinkGenPropertyTrees, possibly because of better raster invalidation tracking.
 

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	clip.png 397 KB View Download

Deleted: sb.html 356 bytes

sb.html 356 bytes View Download

Chrome Version: 73.0.3642.0/dev
OS: MacOs

What steps will reproduce the problem?
(1) Open the attached testcase
(2) Scroll up and down with a scroll wheel or the trackpad.
(3) Notice the green box does not redraw fully sometimes (is clipped).

What is the expected result?
The green box should scroll smoothly.

What happens instead?
The green box does not fully re-draw sometimes.

I was not able to reproduce this on linux with the scroll wheel. I was able to reproduce this on linux by enabling touch events using devtools and doing a touch-scroll up and down rapidly.

This is a regression from:
[Blink] Avoid SetShouldFlattenTransform() back and forth
https://chromium-review.googlesource.com/c/chromium/src/+/780803/
This patch stopped aggressively invalidating layers which probably exposed the real underlying bug.

This seems to be fixed by --enable-blink-features=BlinkGenPropertyTrees, possibly because of better raster invalidation tracking.
 

Deleted: clip.png 397 KB

	clip.png 397 KB View Download

Deleted: sb.html 356 bytes

sb.html 356 bytes View Download