Support :hover/:active in quirks when leftmost in compound.

LayoutTests/fast/css/hover-leftmost-quirks.html

Index: LayoutTests/fast/css/hover-leftmost-quirks.html
diff --git a/LayoutTests/fast/css/hover-leftmost-quirks.html b/LayoutTests/fast/css/hover-leftmost-quirks.html
new file mode 100644
index 0000000000000000000000000000000000000000..fa8dda1f78ed7ca43254eb68eb8ff08bceecb2ad
--- /dev/null
+++ b/LayoutTests/fast/css/hover-leftmost-quirks.html
@@ -0,0 +1,34 @@
+<!-- quirks mode -->
+<script src="../../resources/js-test.js"></script>
+<style>
+:hover#t1,
+:hover.c2,
+:hover[a3] { background-color: green }
+</style>
+<div id="t1">Green background when hovered</div>
+<div id="t2" class="c2">Green background when hovered</div>
+<div id="t3" a3>Green background when hovered</div>
+<script>
+description("Quirks mode - simple selectors right of :hover");
+
+function moveTo(element) {
+    eventSender.mouseMoveTo(element.offsetLeft + 1,  element.offsetTop + 1);
+}
+
+var transparent = "rgba(0, 0, 0, 0)";
+var green = "rgb(0, 128, 0)";
+
+shouldBeDefined("window.eventSender");
+
+shouldBe("getComputedStyle(t1).backgroundColor", "transparent");
+moveTo(t1);
+shouldBe("getComputedStyle(t1).backgroundColor", "green");
+
+shouldBe("getComputedStyle(t2).backgroundColor", "transparent");
+moveTo(t2);
+shouldBe("getComputedStyle(t2).backgroundColor", "green");
+
+shouldBe("getComputedStyle(t3).backgroundColor", "transparent");
+moveTo(t3);
+shouldBe("getComputedStyle(t3).backgroundColor", "green");
+</script>