Volume: Make VolumeUI startup configurable.

Can now disable the default volume dialog in SystemUI with
a standard product overlay.

Bug: 17753150
Change-Id: I305015dbfc40cde2428fa593c89af0f4568e1b74
diff --git a/packages/SystemUI/src/com/android/systemui/volume/VolumeUI.java b/packages/SystemUI/src/com/android/systemui/volume/VolumeUI.java
index 0586a83..0fe6d89 100644
--- a/packages/SystemUI/src/com/android/systemui/volume/VolumeUI.java
+++ b/packages/SystemUI/src/com/android/systemui/volume/VolumeUI.java
@@ -1,7 +1,6 @@
 package com.android.systemui.volume;
 
 import android.content.Context;
-import android.content.Intent;
 import android.content.res.Configuration;
 import android.database.ContentObserver;
 import android.media.AudioManager;
@@ -11,13 +10,10 @@
 import android.media.session.MediaController;
 import android.media.session.MediaSessionManager;
 import android.net.Uri;
-import android.os.AsyncTask;
 import android.os.Handler;
 import android.os.RemoteException;
-import android.os.UserHandle;
 import android.provider.Settings;
 import android.util.Log;
-import android.view.WindowManagerGlobal;
 
 import com.android.systemui.R;
 import com.android.systemui.SystemUI;
@@ -53,6 +49,7 @@
 
     private final Handler mHandler = new Handler();
 
+    private boolean mEnabled;
     private AudioManager mAudioManager;
     private MediaSessionManager mMediaSessionManager;
     private VolumeController mVolumeController;
@@ -63,6 +60,8 @@
 
     @Override
     public void start() {
+        mEnabled = mContext.getResources().getBoolean(R.bool.enable_volume_ui);
+        if (!mEnabled) return;
         mAudioManager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
         mMediaSessionManager = (MediaSessionManager) mContext
                 .getSystemService(Context.MEDIA_SESSION_SERVICE);
@@ -84,6 +83,7 @@
 
     @Override
     public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
+        pw.print("mEnabled="); pw.println(mEnabled);
         if (mPanel != null) {
             mPanel.dump(fd, pw, args);
         }