Investigate whether or not table cells and other table parts could support relative positioning to enable us to remove the hacks that have built up around this area.
Created attachment 85579 [details]
Stacking test for table cells with relative positioning.
The first test is a stacking test. It shows that position:relative on table cells does in fact affect stacking order in both FFX and IE.
Created attachment 85580 [details]
Offset test for table cells with relative positioning.
Offset test for relative positioning. Results show that IE8 does in fact respect left/top as well as position:relative on table cells. FFX does not respect the offsets.
Created attachment 85581 [details]
Containing block test for table cells with relative positioning
Third test, a containing block test. IE8 supports the relative positioned table cell acting as a containing block for absolutely positioned descendants. Firefox does not.
As far as I can tell we can safely enable relative positioning on table cells. IE fully supports it, so we can too.
When a fix for this lands, http://trac.webkit.org/changeset/80814 should be reverted.
Created attachment 85710 [details]
Attachment 85710 [details] did not pass style-queue:
Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'LayoutTests/ChangeLog', u'LayoutTests/fast..." exit_code: 1
Source/WebCore/css/CSSStyleSelector.cpp:1938: Boolean expressions that span multiple lines should have their operators on the left side of the line instead of the right side. [whitespace/operators] 
Total errors found: 1 in 14 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Fixed in r81049.