Add dispatch key shortcut window callback.

Enables Activities and Dialogs to implement key shortcut behavior.
Useful for global key shortcuts that are not bound to the focused
view or to a menu.

Change-Id: If377d20b227ee1c5cac84c47c9630b2d77f67e2c
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 9550090..48f9e81 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -4768,7 +4768,10 @@
     }
 
     /**
-     * Called when an unhandled key shortcut event occurs.
+     * Called on the focused view when a key shortcut event is not handled.
+     * Override this method to implement local key shortcuts for the View.
+     * Key shortcuts can also be implemented by setting the
+     * {@link MenuItem#setShortcut(char, char) shortcut} property of menu items.
      *
      * @param keyCode The value in event.getKeyCode().
      * @param event Description of the key event.