Always use an ancestor scroll clip of all direct children, or the original
scroll clip if the children don't share the same scroll clip tree.
Unfortunately this requires another pass over the stacking context display list.
Also, fix clips, scroll clips and creation order of blend items:
If a clipped mix-blend-mode item contains absolute / fixed positioned items,
those items should not be clipped, same for blend container items.
When a transform item contains blend modes, create the blend container inside
the transform.
Don't do tree comparisons on scroll clips from different scroll clip trees.
If the inner scroll clip is nullptr, because it was cleared, it will look like
it's the ancestor of the outer non-nullptr scroll clip.
These changes don't look very related, but it was very hard to get tests passing
with only some of the changes and not the others, and after having spent two
weeks on this patch I'm not thrilled about going back and checking exactly which
change was necessary to fix which test failure.
MozReview-Commit-ID: IKGciUBrdNa
--HG--
extra : rebase_source : e570f16ecedd80cba16051f0e1ac66764bc95815
extra : histedit_source : fcfbcbc254aaf93594d9d80c117d6ec945805993
* Add a reftest for checking that blending takes place between a blended child element that is clipped by a rounded rect and its parent element (which has overflow hidden, and rounded corners).
* Add a reftest to check the behavior described in bug 947121 no longer reproduces.
* 5.3.1: Blending between the background layers and the background color for an element with background-blend-mode. Most of section 5.3.1 is covered by other tests. Add the missing tests of the 5.3.1 section of the test plan.
- Test 9: SVG image and background color (SVG as data:uri)
- Test 10: Animated gif image and background color
- Test 12: background-blend-mode on element with 3D transform
* 5.3.2: Background layers do not blend with content outside the background (or behind the element).
- Implementation of tests 2 and 3. Test 1 is already covered by background-blending-isolation.html.
* 5.3.6: background-blend-mode for an element with background-position
* 5.3.7: background-blend-mode for an element with background-size
* 5.3.8: background-blend-mode for an element with background-repeat
* 5.3.9: background-blend-mode for an element with background-clip
* 5.3.10: background-blend-mode for an element with background-origin
* 5.3.11: background-blend-mode for an element with background-attachement
* Add extra tests for the background-blend-mode CSS property: Add some invalid values to the background-blend-mode property definition so that it can benefit from existing invalid property tests.
Manish Goregaokar
Shing Lyu
David Anderson
Markus Stange
Mason Chang
Bas Schouten
David Anderson
Andrew Comminos
Alexandre Lissy
Phil Ringnalda
L. David Baron
Max Vujovic
Rik Cabanier
Ryan VanderMeulen
Horia Iosif Olaru