Bug 78370 – [chromium] compositing/rubberbanding tests failing

• Status: RESOLVED
• Resolution: FIXED
• Component: Tools / Tests

[Tony Chang]

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=platform%2Fchromium%2Fcompositing%2Frubberbanding%2Ftransform-overhang-nw.html%2Cplatform%2Fchromium%2Fcompositing%2Frubberbanding%2Ftransform-overhang-sw.html%2Cplatform%2Fchromium%2Fcompositing%2Frubberbanding%2Ftransform-overhang-n.html%2Cplatform%2Fchromium%2Fcompositing%2Frubberbanding%2Ftransform-overhang-ne.html%2Cplatform%2Fchromium%2Fcompositing%2Frubberbanding%2Ftransform-overhang-size-change.html%2Cplatform%2Fchromium%2Fcompositing%2Frubberbanding%2Ftransform-overhang-w.html

There has been a lot of test flipping that makes it hard for me to tell what caused the most recent failure.  According to the flakiness dashboard, the regression is in this range: http://trac.webkit.org/log/?verbose=on&rev=107345&stop_rev=107313

The most likely change is http://trac.webkit.org/changeset/107335/ or http://trac.webkit.org/changeset/107329/ .

[Tony Chang]

James can you take a look?  I'm going to mark the tests as failing for now.

[Tony Chang]

See also bug 78008.

Looking at the flaky runs of green/non-green results, the non-green results have tiny pixel differences in the rubber band gradients only.

Is that a known cause of flakyness with the compositing path? It seems the non-compositing rubber-banding tests don't have this flakyness in the gradients.

And then there's the more recent regression that just causes them to fail all the time due to not pattern/gradient area being drawn at all...

Pretty sure it's the mock scrollbars change. Rubber-band overhang painting is done by ScrollbarThemeChromiumMac.mm, while the mock scrollbar changes replaces this by ScrollbarThemeMock.

Created attachment 127389 [details]
Patch

[James Robinson]

Comment on attachment 127389 [details]
Patch

If you want these specific tests to not use mock scrollbars, then just call window.internals.settings.setMockScrollbarsEnabled(false) in the tests

Created attachment 127415 [details]
Patch

Comment on attachment 127415 [details]
Patch

New patch that just changes the tests to disable mock scrollbars.

[James Robinson]

Comment on attachment 127415 [details]
Patch

r=me

[WebKit Review Bot]

Comment on attachment 127415 [details]
Patch

Clearing flags on attachment: 127415

Committed r108000: <http://trac.webkit.org/changeset/108000>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.