Fix problems on changing 'multiple' state SELECT element to 'single' state.

third_party/WebKit/LayoutTests/fast/forms/select/select-ask-for-reset.html

Index: third_party/WebKit/LayoutTests/fast/forms/select/select-ask-for-reset.html
diff --git a/third_party/WebKit/LayoutTests/fast/forms/select/select-ask-for-reset.html b/third_party/WebKit/LayoutTests/fast/forms/select/select-ask-for-reset.html
index 3f2b430480efe4e494a8e9bf21698852c5281168..5102576d99c415ff36a31319f888dbf049c6975d 100644
--- a/third_party/WebKit/LayoutTests/fast/forms/select/select-ask-for-reset.html
+++ b/third_party/WebKit/LayoutTests/fast/forms/select/select-ask-for-reset.html
@@ -49,5 +49,21 @@ test(function() {
     select.removeChild(select.lastChild);
     assert_equals(select.selectedIndex, 0);
 }, 'Removing an OPTION from a SELECT element should reset selection.');
+
+test(function() {
+    var select = document.createElement('select');
+    select.multiple = true;
+    select.innerHTML = '<option selected>foo</option><option selected>bar</option>';
+    document.body.appendChild(select);
+    select.removeAttribute('multiple');
+    assert_equals(select.selectedOptions.length, 1);
+    assert_equals(select.selectedIndex, 0, 'The first selected OPTION should be chosen.');
+
+    select.selectedIndex = -1;
+    select.multiple = true;
+    select.multiple = false;
+    assert_equals(select.selectedOptions.length, 1);
+    assert_equals(select.selectedIndex, 0);
+}, 'Changing multiple SELECT to single should reset selection.');
 </script>
 </body>