bindings: Ignores the last undefined arguments when counting the args.

third_party/WebKit/LayoutTests/fast/events/clipboard-clearData.html

Index: third_party/WebKit/LayoutTests/fast/events/clipboard-clearData.html
diff --git a/third_party/WebKit/LayoutTests/fast/events/clipboard-clearData.html b/third_party/WebKit/LayoutTests/fast/events/clipboard-clearData.html
index 744bc277a0ac366be557a5e2ebae182a37745b82..94c7f1805c50333bb1cddd79336c7490c463bb20 100644
--- a/third_party/WebKit/LayoutTests/fast/events/clipboard-clearData.html
+++ b/third_party/WebKit/LayoutTests/fast/events/clipboard-clearData.html
@@ -15,7 +15,6 @@ function copy(event)
     testDataTransfer.setData('custom-data', 'hello world');
 
     shouldNotThrow('testDataTransfer.clearData(null)'); // Gets converted to "null" string.
-    shouldNotThrow('testDataTransfer.clearData(undefined)'); // Gets converted to "undefined" string.
 
     shouldBeEqualToString('testDataTransfer.getData("text")', 'sample');
     shouldBeEqualToString('testDataTransfer.getData("url")', 'http://www.google.com/');
@@ -33,6 +32,17 @@ function copy(event)
     shouldBeEqualToString('testDataTransfer.getData("url")', '');
     shouldBeEqualToString('testDataTransfer.getData("text/html")', '');
     shouldBeEqualToString('testDataTransfer.getData("custom-data")', '');
+
+    testDataTransfer.setData('text', 'sample');
+    testDataTransfer.setData('url', 'http://www.google.com/');
+    testDataTransfer.setData('text/html', '<em>Markup</em>');
+    testDataTransfer.setData('custom-data', 'hello world');
+    // clearData(undefined) is equivalent to clearData().
+    shouldNotThrow('testDataTransfer.clearData(undefined)');
+    shouldBeEqualToString('testDataTransfer.getData("text")', '');
+    shouldBeEqualToString('testDataTransfer.getData("url")', '');
+    shouldBeEqualToString('testDataTransfer.getData("text/html")', '');
+    shouldBeEqualToString('testDataTransfer.getData("custom-data")', '');
 }
 </script>
 </head>