Tests are failing on the WK2 bots after this change:
They are failing because I checked in updated results that expect fixed positioning to create a stacking context. However, WebKitTestRunner does not enable ScrollingCoordinator, so the code that I added to enable stacking contexts for fixedPos is never actually running.
Created attachment 164259 [details]
Attachment 164259 [details] did not pass style-queue:
Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebKit2/ChangeLog', u'Source/WebKit..." exit_code: 1
Source/WebKit2/WebProcess/WebPage/DrawingAreaImpl.cpp:275: One line control clauses should not use braces. [whitespace/braces] 
Total errors found: 1 in 2 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Comment on attachment 164259 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=164259&action=review
> + actually running. This patch moves that code to a place where is will
is => it
> + run for the testing tools, which matches the match for WK1.
"the match for"
Thank you! I fixed the typos and style problem:
Beth, is it possible this broke the functionality of http://trac.webkit.org/changeset/128652?
I see layers for position: fixed stuff on Google+ between 128652 and this patch, but not afterwards...
This appears to have made other tests fail, bug 96945.
Unlike what Tim is seeing, there are extra layers on the tests.