Reviewed by Sam Weinig.

WebCore: 

Test: fast/dom/remove-children-notification-order.html

* dom/ContainerNode.cpp:
(WebCore::ContainerNode::removeChildren): Changed to call childrenChanged()
before calling removedFromDocument() on each removed child, which matches
the order removeChild() does things, and avoids the assertion. This required
temporarily storing the removed children in a vector.
Also added comments about other discrepancies between this function and
removeChild().

LayoutTests: 

* fast/dom/remove-children-notification-order-expected.txt: Added.
* fast/dom/remove-children-notification-order.html: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@55462 268f45cc-cd09-0410-ab3c-d52691b4dbfc