Enforce containing block requirement for IntersectionObserver.

third_party/WebKit/LayoutTests/intersection-observer/containing-block-expected.txt

Index: third_party/WebKit/LayoutTests/intersection-observer/containing-block-expected.txt
diff --git a/third_party/WebKit/LayoutTests/intersection-observer/containing-block-expected.txt b/third_party/WebKit/LayoutTests/intersection-observer/containing-block-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..94353bcb25526b3d6c354918b2f43f3d04e843c6
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/intersection-observer/containing-block-expected.txt
@@ -0,0 +1,40 @@
+Test that no notifications are generated when root is not in the containing block chain of target.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS entries.length is 0
+PASS entries.length is 1
+PASS entries[0].boundingClientRect.left is 58
+PASS entries[0].boundingClientRect.right is 158
+PASS entries[0].boundingClientRect.top is 18
+PASS entries[0].boundingClientRect.bottom is 118
+PASS entries[0].intersectionRect.left is 58
+PASS entries[0].intersectionRect.right is 158
+PASS entries[0].intersectionRect.top is 18
+PASS entries[0].intersectionRect.bottom is 118
+PASS entries[0].rootBounds.left is 8
+PASS entries[0].rootBounds.right is 193
+PASS entries[0].rootBounds.top is 8
+PASS entries[0].rootBounds.bottom is 208
+PASS entries[0].target is [object HTMLDivElement]
+PASS entries.length is 2
+PASS entries[1].boundingClientRect.left is 58
+PASS entries[1].boundingClientRect.right is 158
+PASS entries[1].boundingClientRect.top is 258
+PASS entries[1].boundingClientRect.bottom is 358
+PASS entries[1].intersectionRect.left is 0
+PASS entries[1].intersectionRect.right is 0
+PASS entries[1].intersectionRect.top is 0
+PASS entries[1].intersectionRect.bottom is 0
+PASS entries[1].rootBounds.left is 8
+PASS entries[1].rootBounds.right is 193
+PASS entries[1].rootBounds.top is 8
+PASS entries[1].rootBounds.bottom is 208
+PASS entries[1].target is [object HTMLDivElement]
+PASS entries.length is 2
+PASS entries.length is 2
+PASS successfullyParsed is true
+
+TEST COMPLETE
+