Fix issue in which removing a class does not always invalidate style

LayoutTests/fast/css/invalidation/targeted-class-style-invalidation.html

Index: LayoutTests/fast/css/invalidation/targeted-class-style-invalidation.html
diff --git a/LayoutTests/fast/css/invalidation/targeted-class-style-invalidation.html b/LayoutTests/fast/css/invalidation/targeted-class-style-invalidation.html
index b229f9faf2840bf3c33d4221c1f00614f3ff9d70..60e293328a20456324165b5e989217b8f121a7be 100644
--- a/LayoutTests/fast/css/invalidation/targeted-class-style-invalidation.html
+++ b/LayoutTests/fast/css/invalidation/targeted-class-style-invalidation.html
@@ -2,11 +2,14 @@
 <script src="../../../resources/js-test.js"></script>
 
 <style>
-  .outer .inner {}
+  div { width: 100px }
+  .outer .inner { width: 200px }
 </style>
 
 <div id="outer">
     <div id="inner" class="inner">
+        <div id="innerChild">

[rune, 2014/02/18 22:13:24]

Nit: "innerChild" id unused. Would make sense to have it if you referred to it
in a comment like you did for "inner2".

[chrishtr, 2014/02/18 22:33:16]

Done.

+        </div>
     </div>
     <div id="inner2">
     </div>
@@ -23,9 +26,7 @@ function insertStyleSheet(css)
 }
 
 var outer = document.getElementById('outer');
-
-outer.offsetTop;
-outer.className = 'outer';
+var inner = document.getElementById('inner');
 
 // Style recalc should happen on "inner" and "outer", but not "inner2".
 
@@ -33,8 +34,21 @@ var count;
 if (internals.runtimeFlags.targetedStyleRecalcEnabled)
     count = 2;
 else
-    count = 3;
+    count = 4;
+
+outer.offsetTop;
+outer.className = 'outer';
+shouldBe("internals.updateStyleAndReturnAffectedElementCount()", '' + count);
+shouldBe("getComputedStyle(inner).width", '"200px"');
+
+if (internals.runtimeFlags.targetedStyleRecalcEnabled)
+    count = 1;
+else
+    count = 2;
 
+inner.offsetTop;
+inner.className = '';
 shouldBe("internals.updateStyleAndReturnAffectedElementCount()", '' + count);
+shouldBe("getComputedStyle(inner).width", '"100px"');
 
 </script>