stagefright: define CB_CODEC_RELEASED and ReleaseReason enum.

Bug: 19620911
Change-Id: I95e257c8aea2ef218f27ffaa2e62a8f12554d824
diff --git a/include/media/stagefright/MediaCodec.h b/include/media/stagefright/MediaCodec.h
index d055341..4ddb8d4 100644
--- a/include/media/stagefright/MediaCodec.h
+++ b/include/media/stagefright/MediaCodec.h
@@ -51,7 +51,13 @@
         CB_OUTPUT_AVAILABLE = 2,
         CB_ERROR = 3,
         CB_OUTPUT_FORMAT_CHANGED = 4,
-        CB_RESOURCE_RECLAIMED = 5,
+        CB_CODEC_RELEASED = 5,
+    };
+
+    // used by CB_CODEC_RELEASED to tell the upper layer the cause of the release.
+    enum ReleaseReason {
+        REASON_UNKNOWN = 0,
+        REASON_RECLAIMED,  // resources reclaimed by resource manager
     };
 
     struct BatteryNotifier;