Ignore mouseup shortly after showing cr.ui.Menu

chrome/test/data/webui/menu_test.html

Index: chrome/test/data/webui/menu_test.html
diff --git a/chrome/test/data/webui/menu_test.html b/chrome/test/data/webui/menu_test.html
index 7e0e9205a06d1766491e64abf1a9c0e387aebfd6..83b188fcbdce611a62d4816a20f210340fdc9942 100644
--- a/chrome/test/data/webui/menu_test.html
+++ b/chrome/test/data/webui/menu_test.html
@@ -18,6 +18,36 @@ function testHandleMouseOver() {
   assertTrue(called);
 }
 
+function testHandleMouseUp() {
+  var realNow = Date.now;
+  Date.now = function() { return 10; };
+
+  var menu = new cr.ui.Menu;
+  menu.show({x: 5, y: 5});
+
+  function mouseUpAt(x, y) {
+    return menu.dispatchEvent(new MouseEvent('mouseup', {
+      bubbles: true,
+      cancelable: true,
+      target: menu,
+      screenX: x,
+      screenY: y,
+    }));
+  }
+
+  // Stop mouseups at the same time and position.
+  assertFalse(mouseUpAt(5, 5));
+
+  // Allow mouseups with different positions but the same time.
+  assertTrue(mouseUpAt(50, 50));
+
+  // Alow mouseups with the same position but different times.
+  Date.now = function() { return 1000; };
+  assertTrue(mouseUpAt(5, 5));
+
+  Date.now = realNow;
+}
+
 </script>
 </body>
 </html>