Fix an assertion failure in rendererIsFocusable of form controls.

LayoutTests/fast/forms/label/label-assertion-with-active-style.html

Index: LayoutTests/fast/forms/label/label-assertion-with-active-style.html
diff --git a/LayoutTests/fast/forms/label/label-assertion-with-active-style.html b/LayoutTests/fast/forms/label/label-assertion-with-active-style.html
new file mode 100644
index 0000000000000000000000000000000000000000..927347ffc3f4b543e27e37db977a34ed3a7907ab
--- /dev/null
+++ b/LayoutTests/fast/forms/label/label-assertion-with-active-style.html
@@ -0,0 +1,14 @@
+<script src="../resources/common.js"></script>
+<script src="../../js/resources/js-test-pre.js"></script>
+<style>
+input:active {
+    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.12);
+}
+</style>
+<input id="show-home-button">
+<label for="show-home-button">Show Home Button</label>
+<script>
+clickElement(document.querySelector('label'));
+testPassed('if not crashed.');
+</script>
+<script src="../../js/resources/js-test-post.js"></script>