Add root margin support for IntersectionObserver.

third_party/WebKit/LayoutTests/intersection-observer/root-margin-expected.txt

Index: third_party/WebKit/LayoutTests/intersection-observer/root-margin-expected.txt
diff --git a/third_party/WebKit/LayoutTests/intersection-observer/root-margin-expected.txt b/third_party/WebKit/LayoutTests/intersection-observer/root-margin-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..40ef5e66d8acad19b82618e6d323d64977a5d34d
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/intersection-observer/root-margin-expected.txt
@@ -0,0 +1,47 @@
+Intersection observer test with root margin and implicit root.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS new IntersectionObserver(observer_callback, { rootMargin: '1' }) threw exception Error: rootMargin must be specified in pixels or percent..
+PASS new IntersectionObserver(observer_callback, { rootMargin: '1em' }) threw exception Error: rootMargin must be specified in pixels or percent..
+PASS new IntersectionObserver(observer_callback, { rootMargin: 'auto' }) threw exception Error: rootMargin must be specified in pixels or percent..
+PASS new IntersectionObserver(observer_callback, { rootMargin: '1.4px' }) did not throw exception.
+PASS new IntersectionObserver(observer_callback, { rootMargin: '1.4px 2px' }) did not throw exception.
+PASS new IntersectionObserver(observer_callback, { rootMargin: '1.4px 2px 3%' }) did not throw exception.
+PASS new IntersectionObserver(observer_callback, { rootMargin: '1.4px 2px 3% 40px junk junk junk' }) did not throw exception.
+PASS entries.length is 0
+PASS entries.length is 1
+PASS entries[0].boundingClientRect.left is 912
+PASS entries[0].boundingClientRect.right is 1012
+PASS entries[0].boundingClientRect.top is 708
+PASS entries[0].boundingClientRect.bottom is 808
+PASS entries[0].intersectionRect.left is 912
+PASS entries[0].intersectionRect.right is 942
+PASS entries[0].intersectionRect.top is 708
+PASS entries[0].intersectionRect.bottom is 808
+PASS entries[0].rootBounds.left is -30
+PASS entries[0].rootBounds.right is 942
+PASS entries[0].rootBounds.top is -10
+PASS entries[0].rootBounds.bottom is 819
+PASS entries[0].target is [object HTMLDivElement]
+PASS entries.length is 1
+PASS entries.length is 2
+PASS entries[1].boundingClientRect.left is 912
+PASS entries[1].boundingClientRect.right is 1012
+PASS entries[1].boundingClientRect.top is -192
+PASS entries[1].boundingClientRect.bottom is -92
+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 -30
+PASS entries[1].rootBounds.right is 942
+PASS entries[1].rootBounds.top is -10
+PASS entries[1].rootBounds.bottom is 819
+PASS entries[1].target is [object HTMLDivElement]
+PASS successfullyParsed is true
+
+TEST COMPLETE
+  
+