Update HTML parser's foster-parenting algorithm to match the current spec

LayoutTests/fast/parser/foster-parent-expected.txt

Index: LayoutTests/fast/parser/foster-parent-expected.txt
diff --git a/LayoutTests/fast/parser/foster-parent-expected.txt b/LayoutTests/fast/parser/foster-parent-expected.txt
index 3f5e359c9a819e308daccbfee04149e5337c7a9a..23b5eac6a059d9611ccd3847a6bd8bb1a50e752a 100644
--- a/LayoutTests/fast/parser/foster-parent-expected.txt
+++ b/LayoutTests/fast/parser/foster-parent-expected.txt
@@ -1,3 +1,11 @@
-Otherwise, if there is a table element in the stack of open elements, but the last table element in the stack of open elements has no parent, or its parent node is not an element, then the foster parent element is the element before the last table element in the stack of open elements.
+Tests the HTML foster parenting algorithm when a DocumentFragment is the chosen foster parent
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS div.children.length is 0
+PASS docFragment.firstElementChild.tagName is 'H1'
+PASS successfullyParsed is true
+
+TEST COMPLETE
 
-success