Explicitly trigger compositing for layers that need to be moved by ScrollingTreePositionedNodes

• Component: Scrolling
• Status: RESOLVED FIXED

[Simon Fraser (smfr)]

There may be cases where we haven't made a compositing layer for something that needs to be moved around by a positioned node, but maybe we've composited a descendant. We should probably do explicit compositing in some cases.

[Radar WebKit Bug Importer]

<rdar://problem/48867502>

[Simon Fraser (smfr)]

Created attachment 364611 [details]
Testcase that needs this

[Simon Fraser (smfr)]

Created attachment 364616 [details]
Simpler case

[Simon Fraser (smfr)]

Created attachment 365303 [details]
Patch

[EWS Watchlist]

Comment on attachment 365303 [details]
Patch

Attachment 365303 [details] did not pass mac-wk2-ews (mac-wk2):
Output: https://webkit-queues.webkit.org/results/11576335

New failing tests:
scrollingcoordinator/scrolling-tree/positioned-nodes.html
http/wpt/mediarecorder/MediaRecorder-AV-audio-video-dataavailable.html

[EWS Watchlist]

Created attachment 365321 [details]
Archive of layout-test-results from ews106 for mac-highsierra-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews106  Port: mac-highsierra-wk2  Platform: Mac OS X 10.13.6

[EWS Watchlist]

Comment on attachment 365303 [details]
Patch

Attachment 365303 [details] did not pass ios-sim-ews (ios-simulator-wk2):
Output: https://webkit-queues.webkit.org/results/11577245

New failing tests:
scrollingcoordinator/scrolling-tree/positioned-nodes.html
compositing/layer-creation/absolute-in-async-overflow-scroll.html

[EWS Watchlist]

Created attachment 365329 [details]
Archive of layout-test-results from ews122 for ios-simulator-wk2

The attached test failures were seen while running run-webkit-tests on the ios-sim-ews.
Bot: ews122  Port: ios-simulator-wk2  Platform: Mac OS X 10.13.6

[Simon Fraser (smfr)]

https://trac.webkit.org/r243209

[Truitt Savell]

Looks like the new test compositing/layer-creation/absolute-in-async-overflow-scroll.html

from https://trac.webkit.org/changeset/243209/webkit

is failing. History:
http://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=compositing%2Flayer-creation%2Fabsolute-in-async-overflow-scroll.html

Diff:
--- /Volumes/Data/slave/highsierra-release-tests-wk2/build/layout-test-results/compositing/layer-creation/absolute-in-async-overflow-scroll-expected.txt
+++ /Volumes/Data/slave/highsierra-release-tests-wk2/build/layout-test-results/compositing/layer-creation/absolute-in-async-overflow-scroll-actual.txt
@@ -16,12 +16,12 @@
             (GraphicsLayer
               (offsetFromRenderer width=1 height=1)
               (position 1.00 1.00)
-              (bounds 200.00 200.00)
+              (bounds 185.00 185.00)
               (children 1
                 (GraphicsLayer
                   (offsetFromRenderer width=1 height=1)
                   (anchor 0.00 0.00)
-                  (bounds 200.00 840.00)
+                  (bounds 185.00 841.00)
                   (drawsContent 1)
                   (children 1
                     (GraphicsLayer

[Simon Fraser (smfr)]

Fixed in https://trac.webkit.org/r243228