1136971 - With multi-FrameMetrics, layer border for inner scrollable frame lags while outer frame is async-scrolled

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect)

Description

[Botond Ballo [:botond]]

STR:
  1. Turn on layer borders in the developer settings.
  2. Load http://people.mozilla.org/~bballo/clip.html in the B2G browser.
  3. Scroll the inner (purple) frame to layerize it.
  4. Scroll the outer frame.

Expected results:
  As the outer frame is scrolled, the purple layer border around the
  inner frame moves in sync with the inner frame.

Actual results:
  The layer border lags behind the inner frame.

The issue here is basically the same as in bug 1130982: with multi-FrameMetrics, the composition bounds of scroll frames lower in the metrics stack need to be transformed by the async transform of scroll frames higher in the metrics stack. In bug 1130982, this caused a rendering problem due to the composition bounds being used as the clip rect. Here, it's causing a problem due to the composition bounds being used as the layer border.

Comment 1

[Botond Ballo [:botond]]

Attachment: Fix

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Comment on attachment 8569503 [details] [diff] [review]
Fix

Review of attachment 8569503 [details] [diff] [review]:
-----------------------------------------------------------------

Nice catch!

Comment 3

[Botond Ballo [:botond]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/cfc60f8124bb

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

Backed out in https://hg.mozilla.org/integration/mozilla-inbound/rev/b83ecdab252a for mass crashes like https://treeherder.mozilla.org/logviewer.html#?job_id=7065009&repo=mozilla-inbound and https://treeherder.mozilla.org/logviewer.html#?job_id=7065767&repo=mozilla-inbound

Comment 5

[Botond Ballo [:botond]]

Doh - Layer::GetAsyncPanZoomController() will be null on Android.

Comment 6

[Botond Ballo [:botond]]

Attachment: Fix

Updated to add null check. Carrying r+.

Will wait for a Try push this time. Here's one that includes this patch, and includes Android tests:

https://treeherder.mozilla.org/#/jobs?repo=try&revision=866de5c9fcdc

Comment 7

[Botond Ballo [:botond]]

(In reply to Botond Ballo [:botond] from comment #6)
> https://treeherder.mozilla.org/#/jobs?repo=try&revision=866de5c9fcdc

Try push is green. Setting checkin-needed as m-i is closed.

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/e04b01edb944

Comment 9

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/e04b01edb944