Warn user when max number of tabs is reached

     Bug: http://b/issue?id=3123994
     A toast is shown when the max number of tabs is reached

Change-Id: I5008e227c91139147920fd214f184061f816a353
diff --git a/src/com/android/browser/UI.java b/src/com/android/browser/UI.java
index 2bfec44..b56ba30 100644
--- a/src/com/android/browser/UI.java
+++ b/src/com/android/browser/UI.java
@@ -131,4 +131,7 @@
     View getVideoLoadingProgressView();
 
     void bookmarkedStatusHasChanged(Tab tab);
+
+    void showMaxTabsWarning();
+
 }