Add null parent check to startActionMode

 Bug: 6012515

Change-Id: I9f684bf0fd314285c4d4933ba2a7645f10c9dc7b
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 81151b0..384e39a 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -3631,7 +3631,9 @@
      * @see ActionMode
      */
     public ActionMode startActionMode(ActionMode.Callback callback) {
-        return getParent().startActionModeForChild(this, callback);
+        ViewParent parent = getParent();
+        if (parent == null) return null;
+        return parent.startActionModeForChild(this, callback);
     }
 
     /**