audio: new stream types

Added stream types for internal use by audio policy
and audio flinger.

Bug: 18067208.
Change-Id: I90fd4df9ed5e0d8fb8c220d67e95fd0e32a06f14
diff --git a/include/system/audio.h b/include/system/audio.h
index df454ff..2749ce0 100644
--- a/include/system/audio.h
+++ b/include/system/audio.h
@@ -57,10 +57,14 @@
                                         * and must be routed to speaker
                                         */
     AUDIO_STREAM_DTMF             = 8,
-    AUDIO_STREAM_TTS              = 9,
-
-    AUDIO_STREAM_CNT,
-    AUDIO_STREAM_MAX              = AUDIO_STREAM_CNT - 1,
+    AUDIO_STREAM_TTS              = 9,  /* Transmitted Through Speaker.
+                                         * Plays over speaker only, silent on other devices.
+                                         */
+    AUDIO_STREAM_ACCESSIBILITY    = 10, /* For accessibility talk back prompts */
+    AUDIO_STREAM_REROUTING        = 11, /* For dynamic policy output mixes */
+    AUDIO_STREAM_PATCH            = 12, /* For internal audio flinger tracks. Fixed volume */
+    AUDIO_STREAM_PUBLIC_CNT       = AUDIO_STREAM_TTS + 1,
+    AUDIO_STREAM_CNT              = AUDIO_STREAM_PATCH + 1,
 } audio_stream_type_t;
 
 /* Do not change these values without updating their counterparts