Introduces navigation keycodes.

These four new navigation keycodes are intended to be used to
navigate a tree hierarchy or list of items.  They should be used to
allow the user to advance forward or backward within a list of
sibling items, expand the currently selected item to navigate the
item's children, or back out from the current item to its parent
item or state.

Change-Id: I4781e9d7756ed00ca14d8d4c743da3cc0e68ea6c
diff --git a/include/android/keycodes.h b/include/android/keycodes.h
index 75d0ab6..80e44c0 100644
--- a/include/android/keycodes.h
+++ b/include/android/keycodes.h
@@ -302,7 +302,11 @@
     AKEYCODE_TV_CONTENTS_MENU = 256,
     AKEYCODE_TV_MEDIA_CONTEXT_MENU = 257,
     AKEYCODE_TV_TIMER_PROGRAMMING = 258,
-    AKEYCODE_HELP            = 259
+    AKEYCODE_HELP            = 259,
+    AKEYCODE_NAVIGATE_PREVIOUS = 260,
+    AKEYCODE_NAVIGATE_NEXT   = 261,
+    AKEYCODE_NAVIGATE_IN     = 262,
+    AKEYCODE_NAVIGATE_OUT    = 263
 
     // NOTE: If you add a new keycode here you must also add it to several other files.
     //       Refer to frameworks/base/core/java/android/view/KeyEvent.java for the full list.