Support style invalidation for scrollbar pseudo elements.

LayoutTests/fast/css/invalidation/scrollbar-pseudo-expected.txt

Index: LayoutTests/fast/css/invalidation/scrollbar-pseudo-expected.txt
diff --git a/LayoutTests/fast/css/invalidation/scrollbar-pseudo-expected.txt b/LayoutTests/fast/css/invalidation/scrollbar-pseudo-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..a120d5ffbd71cd3a5c91f691bfeb9cb7bf56fd7d
--- /dev/null
+++ b/LayoutTests/fast/css/invalidation/scrollbar-pseudo-expected.txt
@@ -0,0 +1,45 @@
+Style invalidation for scrollbar pseudo elements.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 3
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar').backgroundColor is green
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 8
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar').backgroundColor is green
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-button').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 7
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-button').backgroundColor is green
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-button').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 12
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-button').backgroundColor is green
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-corner').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 4
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-corner').backgroundColor is green
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-corner').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 9
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-corner').backgroundColor is green
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-thumb').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 4
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-thumb').backgroundColor is green
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-thumb').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 9
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-thumb').backgroundColor is green
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-track').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 4
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-track').backgroundColor is green
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-track').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 9
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-track').backgroundColor is green
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-track-piece').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 5
+PASS getComputedStyle(scroller1, '::-webkit-scrollbar-track-piece').backgroundColor is green
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-track-piece').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 10
+PASS getComputedStyle(scroller2, '::-webkit-scrollbar-track-piece').backgroundColor is green
+PASS successfullyParsed is true
+
+TEST COMPLETE
+