https://bugs.webkit.org/show_bug.cgi?id=99228

Reviewed by Dimitri Glazkov.

Source/WebCore:

We support shadow reprojection; elements distributed to <shadow> element can be reprojected to <content> now.

First, we have a distribution vector for each InsertionPoint, even if InsertionPoint is a shadow insertion point.
And we update a node-distribution map. Basically We're creating a map from node to InsertionPoint in ElementShadow.
If a node can be distributed to several InsertionPoint (e.g. in case reprojection happens),
the InsertionPoint in older ShadowDOM is chosen.

We also fix ComposedShadowTreeWalker to consider shadow reprojection.

Tests: fast/dom/shadow/composed-shadow-tree-walker-shadow-reprojection.html
       fast/dom/shadow/shadow-reprojection-click.html
       fast/dom/shadow/shadow-reprojection-dynamic.html
       fast/dom/shadow/shadow-reprojection-fallback.html
       fast/dom/shadow/shadow-reprojection.html
       fast/dom/shadow/shadow-reprojection2.html

* css/StyleResolver.cpp:
(WebCore::shouldResetStyleInheritance): Now context.insertionPoint() returns the final insertion point where
a node is distributed. So we don't have to trace shadow insertion point anymore here.
(WebCore::StyleResolver::styleForElement): Since a direct child of ShadowRoot can be distributed now. In that case,
we don't have any parentElement. The parent node is a ShadowRoot in that case.
* dom/ComposedShadowTreeWalker.cpp:
(WebCore::nodeCanBeDistributed): If a node can be distributed, returns true.
(WebCore):
(WebCore::resolveReprojection): Resolves content-reprojection and shadow-reprojection both.
(WebCore::ComposedShadowTreeWalker::traverseSiblingOrBackToInsertionPoint):
(WebCore::ComposedShadowTreeWalker::traverseParent):
(WebCore::ComposedShadowTreeWalker::traverseParentBackToYoungerShadowRootOrHost): A case ShadowRoot is assigned
to some InsertionPoint should be handled with in traverseSiblingOrBackToInsertionPoint. So we remove it.
(WebCore::AncestorChainWalker::parent): Now we have a case that a direct child of ShadowRoot can be distributed.
In that case, we should not update m_distributedNode.
* dom/ElementShadow.cpp:
(WebCore::ElementShadow::insertionPointFor): Since we have a distribution vector for each InsertionPoint,
we don't have a special case that a ShadowRoot is assigned to some InsertionPoint. Actually the existing code
is not correct now due to shadow reprojection.
* html/shadow/ContentDistributor.cpp:
(WebCore::ContentDistributor::populate): Populate a POOL. If a node is InsertionPoint, we fill it with the
distributed nodes.
(WebCore):
(WebCore::ContentDistributor::distribute): Since we want to make a distribution vector for each InsertionPoint,
we have to resolve a shadow InsertionPoint
(WebCore::ContentDistributor::distributeNodeChildrenTo):
* html/shadow/ContentDistributor.h:
(ContentDistributor):
* html/shadow/HTMLShadowElement.h:
(WebCore::toHTMLShadowElement):
(WebCore):
* html/shadow/InsertionPoint.h:
(WebCore::parentNodeForDistribution):
(WebCore::parentElementForDistribution):
(WebCore):

LayoutTests:

* fast/dom/shadow/composed-shadow-tree-walker-shadow-reprojection-expected.txt: Added.
* fast/dom/shadow/composed-shadow-tree-walker-shadow-reprojection.html: Added. A walker test case for elements distributed
to shadow element are reprojected.
* fast/dom/shadow/composed-shadow-tree-walker.html:
* fast/dom/shadow/content-reprojection-complex.html:
* fast/dom/shadow/content-reprojection-fallback-expected.html:
* fast/dom/shadow/content-reprojection-fallback-reprojection-expected.html:
* fast/dom/shadow/shadow-reprojection-click-expected.txt: Added.
* fast/dom/shadow/shadow-reprojection-click.html: Added. Does some interactive with a shadow-reprojected node.
* fast/dom/shadow/shadow-reprojection-dynamic-expected.html: Added.
* fast/dom/shadow/shadow-reprojection-dynamic.html: Added. Adds dynamically elements shadow-reprojected.
* fast/dom/shadow/shadow-reprojection-expected.html: Added.
* fast/dom/shadow/shadow-reprojection-fallback-expected.html: Added.
* fast/dom/shadow/shadow-reprojection-fallback.html: Added. A test case for fallback elements of a shadow element
are reprojected.
* fast/dom/shadow/shadow-reprojection-prohibited-expected.html: Removed.
* fast/dom/shadow/shadow-reprojection-prohibited.html: Removed.
* fast/dom/shadow/shadow-reprojection.html: Added. A basic test case.
* fast/dom/shadow/shadow-reprojection2-expected.html: Added.
* fast/dom/shadow/shadow-reprojection2.html: Added. Another basic test case.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@132760 268f45cc-cd09-0410-ab3c-d52691b4dbfc