Reject invert for outline-color at parse time.

third_party/WebKit/LayoutTests/fast/css/outline-currentcolor.html

 <style>
 #test3 { color: blue; }
 </style>
 <div id="test-container">
   <div id="test1" id="one" style="color:green; outline: solid 1em currentColor"></div>
   <div id="test2" id="two" style="color:red; outline: solid 1em currentColor"></div>
   <div style="color:green">
     <div id="test3" style="color:currentColor; outline: solid 1em currentColor"></div>
   </div>
+  <div id="test4" id="four" style="color:green"></div>
 </div>
 <script src="../../resources/js-test.js"></script>
 <script>
 description('Test that outline-color is non-inherit and currentColor is handled correctly.');
 var test1 = document.getElementById("test1");
 var test2 = document.getElementById("test2");
 var test3 = document.getElementById("test3");
+var test3 = document.getElementById("test4");
 test2.style.color = "green";
 shouldBeEqualToString('getComputedStyle(test1).outlineColor', 'rgb(0, 128, 0)');
 shouldBeEqualToString('getComputedStyle(test2).outlineColor', 'rgb(0, 128, 0)');
 shouldBeEqualToString('getComputedStyle(test3).outlineColor', 'rgb(0, 128, 0)');
+shouldBeEqualToString('getComputedStyle(test4).outlineColor', 'rgb(0, 128, 0)');
 </script>