Replace control block frameCount_ by explicit in/out parameter

in IAudioFlinger::createTrack and IAudioFlinger::openRecord

Change-Id: I09c644c80e92c8e744b1b99055988a2588b2a83d
diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h
index 85862a8..b5a4c0b 100644
--- a/include/private/media/AudioTrackShared.h
+++ b/include/private/media/AudioTrackShared.h
@@ -96,11 +96,7 @@
                                         // The value should be used "for entertainment purposes only",
                                         // which means don't make important decisions based on it.
 
-                size_t      frameCount_;    // used during creation to pass actual track buffer size
-                                            // from AudioFlinger to client, and not referenced again
-                                            // FIXME remove here and replace by createTrack() in/out
-                                            // parameter
-                                            // renamed to "_" to detect incorrect use
+                uint32_t    mPad1;      // unused
 
     volatile    int32_t     mFutex;     // event flag: down (P) by client,
                                         // up (V) by server or binderDied() or interrupt()