Distinguish systrace timelines for playback and capture

Bug: 30120068
Change-Id: If416540f0785e83e7b1e8ba986ee55b5b9298a2a
diff --git a/services/audioflinger/FastMixer.cpp b/services/audioflinger/FastMixer.cpp
index 01f3939..b0780a4 100644
--- a/services/audioflinger/FastMixer.cpp
+++ b/services/audioflinger/FastMixer.cpp
@@ -46,7 +46,7 @@
 
 /*static*/ const FastMixerState FastMixer::sInitial;
 
-FastMixer::FastMixer() : FastThread(),
+FastMixer::FastMixer() : FastThread("cycle_ms", "load_us"),
     // mFastTrackNames
     // mGenerations
     mOutputSink(NULL),