Fixes incorrect values seen in clip property

third_party/WebKit/LayoutTests/fast/css/getComputedStyle/computed-style-clip.html

+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<div id="target1" style="clip: rect(auto, auto, auto, auto);"></div>
+<div id="target2" style="clip: rect(auto, auto, auto, 5);"></div>
+<div id="target3" style="clip: rect(5, 2, auto, 5);"></div>
+<script>
+test(function() {
+  // Tests https://code.google.com/p/chromium/issues/detail?id=412921
+  assert_equals(getComputedStyle(target1).clip, 'rect(auto auto auto auto)');
+  assert_equals(getComputedStyle(target2).clip, 'rect(auto auto auto 5px)');
+  assert_equals(getComputedStyle(target3).clip, 'rect(5px 2px auto 5px)');
+});
+</script>