Track pid for each session

so they can be properly freed.

Change-Id: I6f389035bc29e74e7c367c1c6d0252b180f666b3
diff --git a/include/media/IAudioFlinger.h b/include/media/IAudioFlinger.h
index ea225ac..7f53bfc 100644
--- a/include/media/IAudioFlinger.h
+++ b/include/media/IAudioFlinger.h
@@ -180,8 +180,8 @@
 
     virtual int newAudioSessionId() = 0;
 
-    virtual void acquireAudioSessionId(int audioSession) = 0;
-    virtual void releaseAudioSessionId(int audioSession) = 0;
+    virtual void acquireAudioSessionId(int audioSession, pid_t pid) = 0;
+    virtual void releaseAudioSessionId(int audioSession, pid_t pid) = 0;
 
     virtual status_t queryNumberEffects(uint32_t *numEffects) const = 0;