Revert "Revert "AudioFlinger: Keep track of music effect thread ..."

Revert submission 26624467-revert-25712917-SEPJYAPZTA

Reason for revert: b/330202134 fixed with ag/26627359

Reverted changes: /q/submissionid:26624467-revert-25712917-SEPJYAPZTA

Change-Id: I0a43627e18368f3b883e9d3e33d60d679f2920d5
diff --git a/services/audioflinger/IAfThread.h b/services/audioflinger/IAfThread.h
index d701288..4b6ab89 100644
--- a/services/audioflinger/IAfThread.h
+++ b/services/audioflinger/IAfThread.h
@@ -95,7 +95,8 @@
     virtual bool updateOrphanEffectChains(const sp<IAfEffectModule>& effect)
             EXCLUDES_AudioFlinger_Mutex = 0;
     virtual status_t moveEffectChain_ll(audio_session_t sessionId,
-            IAfPlaybackThread* srcThread, IAfPlaybackThread* dstThread)
+            IAfPlaybackThread* srcThread, IAfPlaybackThread* dstThread,
+            IAfEffectChain* srcChain = nullptr)
             REQUIRES(mutex(), audio_utils::ThreadBase_Mutex) = 0;
 
     virtual void requestLogMerge() = 0;