fix new tab regression

Change-Id: I788343c7df3c282d8f42aeac715ad54eacea77b9
diff --git a/src/com/android/browser/NavScreen.java b/src/com/android/browser/NavScreen.java
index 4095a96..9f2d4ae 100644
--- a/src/com/android/browser/NavScreen.java
+++ b/src/com/android/browser/NavScreen.java
@@ -239,7 +239,7 @@
             showMenu();
         } else if (mNewIncognito == v) {
             mUi.hideNavScreen(true);
-            mUiController.openTab(null, true, true, false);
+            mUiController.openIncognitoTab();
         }
     }