Merge r222167 - Avoid style resolution when clearing focused element.

https://bugs.webkit.org/show_bug.cgi?id=176224
<rdar://problem/34206409>

Reviewed by Zalan Bujtas.

LayoutTests:

* fast/dom/focus-style-resolution-expected.txt: Added.
* fast/dom/focus-style-resolution.html: Added.

LayoutTests/ChangeLog

@@ -1,3 +1,14 @@
+2017-09-18  Antti Koivisto  <antti@apple.com>
+
+        Avoid style resolution when clearing focused element.
+        https://bugs.webkit.org/show_bug.cgi?id=176224
+        <rdar://problem/34206409>
+
+        Reviewed by Zalan Bujtas.
+
+        * fast/dom/focus-style-resolution-expected.txt: Added.
+        * fast/dom/focus-style-resolution.html: Added.
+
 2017-09-15  Wenson Hsieh  <wenson_hsieh@apple.com>
 
         Avoid style recomputation when forwarding a focus event to an text field's input type

LayoutTests/fast/dom/focus-style-resolution-expected.txt

@@ -0,0 +1,2 @@
+This test passes if it doesn't assert or crash.
+

LayoutTests/fast/dom/focus-style-resolution.html

@@ -0,0 +1,31 @@
+<script>
+if (window.testRunner) {
+    testRunner.dumpAsText();
+    testRunner.waitUntilDone();
+}
+function eventhandler1() {
+txt.appendChild(kg);
+}
+
+function eventhandler2() {
+anim.appendChild(kg);
+}
+
+function eventhandler3() {
+table.scrollIntoView(true);
+testRunner.notifyDone();
+}
+
+</script>
+This test passes if it doesn't assert or crash.
+<table id="table"></table>
+<form>
+<input id="kg" autofocus="autofocus">
+</form>
+<svg>
+<animate id="anim" attributeName="text-anchor" from="middle" to="inherit" onbegin="eventhandler1()" />
+<text id="txt" onload="eventhandler3()">
+<font color="white"></font>
+<select onfocus="eventhandler2()" autofocus="autofocus">
+<textarea>a</textarea>
+<iframe onload="eventhandler1()"></iframe>