Use callbacks for Midi I/O

Instead of having the Sonivox engine directly open the file and
use stdio to read from it, use caller-provided callbacks.

Change-Id: I4d775c8458c48c591a15794c4517e006dcf034e1
diff --git a/include/media/JetPlayer.h b/include/media/JetPlayer.h
index 388f767..63d1980 100644
--- a/include/media/JetPlayer.h
+++ b/include/media/JetPlayer.h
@@ -22,6 +22,7 @@
 #include <libsonivox/jet.h>
 #include <libsonivox/eas_types.h>
 #include <media/AudioTrack.h>
+#include <media/MidiIoWrapper.h>
 
 
 namespace android {
@@ -86,15 +87,13 @@
 
     int                 mMaxTracks; // max number of MIDI tracks, usually 32
     EAS_DATA_HANDLE     mEasData;
-    EAS_FILE_LOCATOR    mEasJetFileLoc;
+    sp<MidiIoWrapper>   mIoWrapper;
     EAS_PCM*            mAudioBuffer;// EAS renders the MIDI data into this buffer,
     sp<AudioTrack>      mAudioTrack; // and we play it in this audio track
     int                 mTrackBufferSize;
     S_JET_STATUS        mJetStatus;
     S_JET_STATUS        mPreviousJetStatus;
 
-    char                mJetFilePath[PATH_MAX];
-
     class JetPlayerThread : public Thread {
     public:
         JetPlayerThread(JetPlayer *player) : mPlayer(player) {