BufferingSettings: hook up internal BufferingSettings API.

Test: compiles
Bug: 32524218

Change-Id: I4b3f1689681560f0c1af3bfc62adee1ce630e218
diff --git a/include/media/BufferingSettings.h b/include/media/BufferingSettings.h
index 7dd9d40..281a5c1 100644
--- a/include/media/BufferingSettings.h
+++ b/include/media/BufferingSettings.h
@@ -40,6 +40,8 @@
     static const int kNoWatermark = -1;
 
     static bool IsValidBufferingMode(int mode);
+    static bool IsTimeBasedBufferingMode(int mode);
+    static bool IsSizeBasedBufferingMode(int mode);
 
     BufferingMode mInitialBufferingMode;  // for prepare
     BufferingMode mRebufferingMode;  // for playback