AudioPolicyService InputDesc minor cleanup

Add a non-default constructor to set the mSessionId, and make mSessionId const.

Remove explicit clear on mEffects - it is automatically cleared by the destructor.

AudioPolicyService::setPreProcessorEnabled:
 - parameter is const *
 - use an alias instead of making a Vector copy

Destructor doesn't need to be virtual since there are no subclasses.

Change-Id: Ibc3c3bea8259839430b1cf5356186c7d96f1082f
diff --git a/services/audioflinger/AudioPolicyService.h b/services/audioflinger/AudioPolicyService.h
index 962c917..106bf6a 100644
--- a/services/audioflinger/AudioPolicyService.h
+++ b/services/audioflinger/AudioPolicyService.h
@@ -279,15 +279,15 @@
 
     class InputDesc {
     public:
-        InputDesc() {}
-        virtual ~InputDesc() {}
-        int mSessionId;
+        InputDesc(int session) : mSessionId(session) {}
+        /*virtual*/ ~InputDesc() {}
+        const int mSessionId;
         Vector< sp<AudioEffect> >mEffects;
     };
 
     static const char * const kInputSourceNames[AUDIO_SOURCE_CNT -1];
 
-    void setPreProcessorEnabled(InputDesc *inputDesc, bool enabled);
+    void setPreProcessorEnabled(const InputDesc *inputDesc, bool enabled);
     status_t loadPreProcessorConfig(const char *path);
     status_t loadEffects(cnode *root, Vector <EffectDesc *>& effects);
     EffectDesc *loadEffect(cnode *root);