For performance, return large objects by reference

Change-Id: Ibf737018ef1d3c7d717584615dcb2d4ecdb50c99
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 766ba44..16048c8 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -1325,7 +1325,8 @@
 
         // get a list of effect modules to suspend when an effect of the type
         // passed is enabled.
-        Vector< sp<EffectModule> > getSuspendEligibleEffects();
+        void                       getSuspendEligibleEffects(Vector< sp<EffectModule> > &effects);
+
         // get an effect module if it is currently enable
         sp<EffectModule> getEffectIfEnabled(const effect_uuid_t *type);
         // true if the effect whose descriptor is passed can be suspended