Clean up AudioRouting API internals.

Reuse existing OnRoutingChangedListener APIs and internal logic by
extending the new AudioRouting.OnRoutingChangedListener.  We use
new default methods to delegate incoming calls on the legacy
interfaces.

Fix a handful of locking bugs.

Bug: 27950070, 27952052, 27949198
Change-Id: Ie584108bcbeeab064d8e27d4984e541f31d36728
diff --git a/api/current.txt b/api/current.txt
index 3444597..3eacdc8 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -19852,8 +19852,8 @@
 
   public class AudioRecord implements android.media.AudioRouting {
     ctor public AudioRecord(int, int, int, int, int) throws java.lang.IllegalArgumentException;
+    method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public deprecated void addOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener, android.os.Handler);
-    method public void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public int getAudioFormat();
     method public int getAudioSessionId();
     method public int getAudioSource();
@@ -19878,8 +19878,8 @@
     method public int read(java.nio.ByteBuffer, int);
     method public int read(java.nio.ByteBuffer, int, int);
     method public void release();
+    method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public deprecated void removeOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener);
-    method public void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public int setNotificationMarkerPosition(int);
     method public int setPositionNotificationPeriod(int);
     method public boolean setPreferredDevice(android.media.AudioDeviceInfo);
@@ -19913,8 +19913,9 @@
     method public abstract void onPeriodicNotification(android.media.AudioRecord);
   }
 
-  public static abstract interface AudioRecord.OnRoutingChangedListener {
+  public static abstract deprecated interface AudioRecord.OnRoutingChangedListener implements android.media.AudioRouting.OnRoutingChangedListener {
     method public abstract void onRoutingChanged(android.media.AudioRecord);
+    method public default void onRoutingChanged(android.media.AudioRouting);
   }
 
   public final class AudioRecordingConfiguration implements android.os.Parcelable {
@@ -19929,10 +19930,10 @@
   }
 
   public abstract interface AudioRouting {
-    method public abstract void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
+    method public abstract void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public abstract android.media.AudioDeviceInfo getPreferredDevice();
     method public abstract android.media.AudioDeviceInfo getRoutedDevice();
-    method public abstract void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
+    method public abstract void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public abstract boolean setPreferredDevice(android.media.AudioDeviceInfo);
   }
 
@@ -19952,8 +19953,8 @@
     ctor public AudioTrack(int, int, int, int, int, int) throws java.lang.IllegalArgumentException;
     ctor public AudioTrack(int, int, int, int, int, int, int) throws java.lang.IllegalArgumentException;
     ctor public AudioTrack(android.media.AudioAttributes, android.media.AudioFormat, int, int, int) throws java.lang.IllegalArgumentException;
+    method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public deprecated void addOnRoutingChangedListener(android.media.AudioTrack.OnRoutingChangedListener, android.os.Handler);
-    method public void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public int attachAuxEffect(int);
     method public void flush();
     method public int getAudioFormat();
@@ -19985,8 +19986,8 @@
     method public void play() throws java.lang.IllegalStateException;
     method public void release();
     method public int reloadStaticData();
+    method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public deprecated void removeOnRoutingChangedListener(android.media.AudioTrack.OnRoutingChangedListener);
-    method public void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public int setAuxEffectSendLevel(float);
     method public int setBufferSizeInFrames(int);
     method public int setLoopPoints(int, int, int);
@@ -20040,8 +20041,9 @@
     method public abstract void onPeriodicNotification(android.media.AudioTrack);
   }
 
-  public static abstract deprecated interface AudioTrack.OnRoutingChangedListener {
-    method public abstract deprecated void onRoutingChanged(android.media.AudioTrack);
+  public static abstract deprecated interface AudioTrack.OnRoutingChangedListener implements android.media.AudioRouting.OnRoutingChangedListener {
+    method public abstract void onRoutingChanged(android.media.AudioTrack);
+    method public default void onRoutingChanged(android.media.AudioRouting);
   }
 
   public class CamcorderProfile {
diff --git a/api/system-current.txt b/api/system-current.txt
index a4927f2..01e0fde 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -21330,8 +21330,8 @@
   public class AudioRecord implements android.media.AudioRouting {
     ctor public AudioRecord(int, int, int, int, int) throws java.lang.IllegalArgumentException;
     ctor public AudioRecord(android.media.AudioAttributes, android.media.AudioFormat, int, int) throws java.lang.IllegalArgumentException;
+    method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public deprecated void addOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener, android.os.Handler);
-    method public void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public int getAudioFormat();
     method public int getAudioSessionId();
     method public int getAudioSource();
@@ -21356,8 +21356,8 @@
     method public int read(java.nio.ByteBuffer, int);
     method public int read(java.nio.ByteBuffer, int, int);
     method public void release();
+    method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public deprecated void removeOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener);
-    method public void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public int setNotificationMarkerPosition(int);
     method public int setPositionNotificationPeriod(int);
     method public boolean setPreferredDevice(android.media.AudioDeviceInfo);
@@ -21393,8 +21393,9 @@
     method public abstract void onPeriodicNotification(android.media.AudioRecord);
   }
 
-  public static abstract interface AudioRecord.OnRoutingChangedListener {
+  public static abstract deprecated interface AudioRecord.OnRoutingChangedListener implements android.media.AudioRouting.OnRoutingChangedListener {
     method public abstract void onRoutingChanged(android.media.AudioRecord);
+    method public default void onRoutingChanged(android.media.AudioRouting);
   }
 
   public final class AudioRecordingConfiguration implements android.os.Parcelable {
@@ -21409,10 +21410,10 @@
   }
 
   public abstract interface AudioRouting {
-    method public abstract void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
+    method public abstract void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public abstract android.media.AudioDeviceInfo getPreferredDevice();
     method public abstract android.media.AudioDeviceInfo getRoutedDevice();
-    method public abstract void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
+    method public abstract void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public abstract boolean setPreferredDevice(android.media.AudioDeviceInfo);
   }
 
@@ -21432,8 +21433,8 @@
     ctor public AudioTrack(int, int, int, int, int, int) throws java.lang.IllegalArgumentException;
     ctor public AudioTrack(int, int, int, int, int, int, int) throws java.lang.IllegalArgumentException;
     ctor public AudioTrack(android.media.AudioAttributes, android.media.AudioFormat, int, int, int) throws java.lang.IllegalArgumentException;
+    method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public deprecated void addOnRoutingChangedListener(android.media.AudioTrack.OnRoutingChangedListener, android.os.Handler);
-    method public void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public int attachAuxEffect(int);
     method public void flush();
     method public int getAudioFormat();
@@ -21465,8 +21466,8 @@
     method public void play() throws java.lang.IllegalStateException;
     method public void release();
     method public int reloadStaticData();
+    method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public deprecated void removeOnRoutingChangedListener(android.media.AudioTrack.OnRoutingChangedListener);
-    method public void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public int setAuxEffectSendLevel(float);
     method public int setBufferSizeInFrames(int);
     method public int setLoopPoints(int, int, int);
@@ -21520,8 +21521,9 @@
     method public abstract void onPeriodicNotification(android.media.AudioTrack);
   }
 
-  public static abstract deprecated interface AudioTrack.OnRoutingChangedListener {
-    method public abstract deprecated void onRoutingChanged(android.media.AudioTrack);
+  public static abstract deprecated interface AudioTrack.OnRoutingChangedListener implements android.media.AudioRouting.OnRoutingChangedListener {
+    method public abstract void onRoutingChanged(android.media.AudioTrack);
+    method public default void onRoutingChanged(android.media.AudioRouting);
   }
 
   public class CamcorderProfile {
diff --git a/api/test-current.txt b/api/test-current.txt
index 4179948..9fb6e24 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -19918,8 +19918,8 @@
 
   public class AudioRecord implements android.media.AudioRouting {
     ctor public AudioRecord(int, int, int, int, int) throws java.lang.IllegalArgumentException;
+    method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public deprecated void addOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener, android.os.Handler);
-    method public void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public int getAudioFormat();
     method public int getAudioSessionId();
     method public int getAudioSource();
@@ -19944,8 +19944,8 @@
     method public int read(java.nio.ByteBuffer, int);
     method public int read(java.nio.ByteBuffer, int, int);
     method public void release();
+    method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public deprecated void removeOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener);
-    method public void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public int setNotificationMarkerPosition(int);
     method public int setPositionNotificationPeriod(int);
     method public boolean setPreferredDevice(android.media.AudioDeviceInfo);
@@ -19979,8 +19979,9 @@
     method public abstract void onPeriodicNotification(android.media.AudioRecord);
   }
 
-  public static abstract interface AudioRecord.OnRoutingChangedListener {
+  public static abstract deprecated interface AudioRecord.OnRoutingChangedListener implements android.media.AudioRouting.OnRoutingChangedListener {
     method public abstract void onRoutingChanged(android.media.AudioRecord);
+    method public default void onRoutingChanged(android.media.AudioRouting);
   }
 
   public final class AudioRecordingConfiguration implements android.os.Parcelable {
@@ -19995,10 +19996,10 @@
   }
 
   public abstract interface AudioRouting {
-    method public abstract void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
+    method public abstract void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public abstract android.media.AudioDeviceInfo getPreferredDevice();
     method public abstract android.media.AudioDeviceInfo getRoutedDevice();
-    method public abstract void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
+    method public abstract void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public abstract boolean setPreferredDevice(android.media.AudioDeviceInfo);
   }
 
@@ -20018,8 +20019,8 @@
     ctor public AudioTrack(int, int, int, int, int, int) throws java.lang.IllegalArgumentException;
     ctor public AudioTrack(int, int, int, int, int, int, int) throws java.lang.IllegalArgumentException;
     ctor public AudioTrack(android.media.AudioAttributes, android.media.AudioFormat, int, int, int) throws java.lang.IllegalArgumentException;
+    method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public deprecated void addOnRoutingChangedListener(android.media.AudioTrack.OnRoutingChangedListener, android.os.Handler);
-    method public void addOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public int attachAuxEffect(int);
     method public void flush();
     method public int getAudioFormat();
@@ -20051,8 +20052,8 @@
     method public void play() throws java.lang.IllegalStateException;
     method public void release();
     method public int reloadStaticData();
+    method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public deprecated void removeOnRoutingChangedListener(android.media.AudioTrack.OnRoutingChangedListener);
-    method public void removeOnRoutingListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public int setAuxEffectSendLevel(float);
     method public int setBufferSizeInFrames(int);
     method public int setLoopPoints(int, int, int);
@@ -20106,8 +20107,9 @@
     method public abstract void onPeriodicNotification(android.media.AudioTrack);
   }
 
-  public static abstract deprecated interface AudioTrack.OnRoutingChangedListener {
-    method public abstract deprecated void onRoutingChanged(android.media.AudioTrack);
+  public static abstract deprecated interface AudioTrack.OnRoutingChangedListener implements android.media.AudioRouting.OnRoutingChangedListener {
+    method public abstract void onRoutingChanged(android.media.AudioTrack);
+    method public default void onRoutingChanged(android.media.AudioRouting);
   }
 
   public class CamcorderProfile {
diff --git a/media/java/android/media/AudioRecord.java b/media/java/android/media/AudioRecord.java
index ca306cc..a5550ec 100644
--- a/media/java/android/media/AudioRecord.java
+++ b/media/java/android/media/AudioRecord.java
@@ -37,6 +37,8 @@
 import android.util.ArrayMap;
 import android.util.Log;
 
+import com.android.internal.annotations.GuardedBy;
+
 /**
  * The AudioRecord class manages the audio resources for Java applications
  * to record audio from the audio input hardware of the platform. This is
@@ -1320,6 +1322,7 @@
      * Note: The query is only valid if the AudioRecord is currently recording. If it is not,
      * <code>getRoutedDevice()</code> will return null.
      */
+    @Override
     public AudioDeviceInfo getRoutedDevice() {
         int deviceId = native_getRoutedDeviceId();
         if (deviceId == 0) {
@@ -1338,8 +1341,8 @@
     /*
      * Call BEFORE adding a routing callback handler.
      */
-    private void testEnableNativeRoutingCallbacks() {
-        if (mRoutingChangeListeners.size() == 0 && mNewRoutingChangeListeners.size() == 0) {
+    private void testEnableNativeRoutingCallbacksLocked() {
+        if (mRoutingChangeListeners.size() == 0) {
             native_enableDeviceCallback();
         }
     }
@@ -1347,24 +1350,23 @@
     /*
      * Call AFTER removing a routing callback handler.
      */
-    private void testDisableNativeRoutingCallbacks() {
-        if (mRoutingChangeListeners.size() == 0 && mNewRoutingChangeListeners.size() == 0) {
+    private void testDisableNativeRoutingCallbacksLocked() {
+        if (mRoutingChangeListeners.size() == 0) {
             native_disableDeviceCallback();
         }
     }
 
     //--------------------------------------------------------------------------
-    // >= "N" (Re)Routing Info
+    // (Re)Routing Info
     //--------------------
     /**
      * The list of AudioRouting.OnRoutingChangedListener interfaces added (with
-     * {@link AudioRecord#addOnRoutingListener(AudioRouting.OnRoutingChangedListener,
-     *      android.os.Handler)}
-     * by an app to receive (re)routing notifications.
+     * {@link AudioRecord#addOnRoutingChangedListener} by an app to receive
+     * (re)routing notifications.
      */
-    private ArrayMap<AudioRouting.OnRoutingChangedListener, NativeNewRoutingEventHandlerDelegate>
-    mNewRoutingChangeListeners =
-        new ArrayMap<AudioRouting.OnRoutingChangedListener, NativeNewRoutingEventHandlerDelegate>();
+    @GuardedBy("mRoutingChangeListeners")
+    private ArrayMap<AudioRouting.OnRoutingChangedListener,
+            NativeRoutingEventHandlerDelegate> mRoutingChangeListeners = new ArrayMap<>();
 
     /**
      * Adds an {@link AudioRouting.OnRoutingChangedListener} to receive notifications of
@@ -1375,14 +1377,15 @@
      * the callback. If <code>null</code>, the {@link Handler} associated with the main
      * {@link Looper} will be used.
      */
-    public void addOnRoutingListener(AudioRouting.OnRoutingChangedListener listener,
+    @Override
+    public void addOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener,
             android.os.Handler handler) {
-        if (listener != null && !mNewRoutingChangeListeners.containsKey(listener)) {
-            synchronized (mNewRoutingChangeListeners) {
-                testEnableNativeRoutingCallbacks();
-                mNewRoutingChangeListeners.put(
-                    listener, new NativeNewRoutingEventHandlerDelegate(this, listener,
-                            handler != null ? handler : new Handler(mInitializationLooper)));
+        synchronized (mRoutingChangeListeners) {
+            if (listener != null && !mRoutingChangeListeners.containsKey(listener)) {
+                testEnableNativeRoutingCallbacksLocked();
+                mRoutingChangeListeners.put(
+                        listener, new NativeRoutingEventHandlerDelegate(this, listener,
+                                handler != null ? handler : new Handler(mInitializationLooper)));
             }
         }
     }
@@ -1393,39 +1396,42 @@
     * @param listener The previously added {@link AudioRouting.OnRoutingChangedListener} interface
     * to remove.
     */
-    public void removeOnRoutingListener(AudioRouting.OnRoutingChangedListener listener) {
-        synchronized (mNewRoutingChangeListeners) {
-            if (mNewRoutingChangeListeners.containsKey(listener)) {
-                mNewRoutingChangeListeners.remove(listener);
-                testDisableNativeRoutingCallbacks();
+    @Override
+    public void removeOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener) {
+        synchronized (mRoutingChangeListeners) {
+            if (mRoutingChangeListeners.containsKey(listener)) {
+                mRoutingChangeListeners.remove(listener);
+                testDisableNativeRoutingCallbacksLocked();
             }
         }
     }
 
     //--------------------------------------------------------------------------
-    // Marshmallow (Re)Routing Info
+    // (Re)Routing Info
     //--------------------
     /**
-     * Defines the interface by which applications can receive notifications of routing
-     * changes for the associated {@link AudioRecord}.
+     * Defines the interface by which applications can receive notifications of
+     * routing changes for the associated {@link AudioRecord}.
+     *
+     * @deprecated users should switch to the general purpose
+     *             {@link AudioRouting.OnRoutingChangedListener} class instead.
      */
-    public interface OnRoutingChangedListener {
+    @Deprecated
+    public interface OnRoutingChangedListener extends AudioRouting.OnRoutingChangedListener {
         /**
-         * Called when the routing of an AudioRecord changes from either and explicit or
-         * policy rerouting. Use {@link #getRoutedDevice()} to retrieve the newly routed-from
-         * device.
+         * Called when the routing of an AudioRecord changes from either and
+         * explicit or policy rerouting. Use {@link #getRoutedDevice()} to
+         * retrieve the newly routed-from device.
          */
         public void onRoutingChanged(AudioRecord audioRecord);
-    }
 
-    /**
-     * The list of AudioRecord.OnRoutingChangedListener interface added (with
-     * {@link AudioRecord#addOnRoutingChangedListener(OnRoutingChangedListener,android.os.Handler)}
-     * by an app to receive (re)routing notifications.
-     */
-    private ArrayMap<OnRoutingChangedListener, NativeRoutingEventHandlerDelegate>
-        mRoutingChangeListeners =
-            new ArrayMap<OnRoutingChangedListener, NativeRoutingEventHandlerDelegate>();
+        @Override
+        default public void onRoutingChanged(AudioRouting router) {
+            if (router instanceof AudioRecord) {
+                onRoutingChanged((AudioRecord) router);
+            }
+        }
+    }
 
     /**
      * Adds an {@link OnRoutingChangedListener} to receive notifications of routing changes
@@ -1435,88 +1441,28 @@
      * @param handler  Specifies the {@link Handler} object for the thread on which to execute
      * the callback. If <code>null</code>, the {@link Handler} associated with the main
      * {@link Looper} will be used.
+     * @deprecated users should switch to the general purpose
+     *             {@link AudioRouting.OnRoutingChangedListener} class instead.
      */
     @Deprecated
     public void addOnRoutingChangedListener(OnRoutingChangedListener listener,
             android.os.Handler handler) {
-        if (listener != null && !mRoutingChangeListeners.containsKey(listener)) {
-            synchronized (mRoutingChangeListeners) {
-                testEnableNativeRoutingCallbacks();
-                mRoutingChangeListeners.put(
-                    listener, new NativeRoutingEventHandlerDelegate(this, listener,
-                            handler != null ? handler : new Handler(mInitializationLooper)));
-            }
-        }
+        addOnRoutingChangedListener((AudioRouting.OnRoutingChangedListener) listener, handler);
     }
 
     /**
       * Removes an {@link OnRoutingChangedListener} which has been previously added
      * to receive rerouting notifications.
      * @param listener The previously added {@link OnRoutingChangedListener} interface to remove.
+     * @deprecated users should switch to the general purpose
+     *             {@link AudioRouting.OnRoutingChangedListener} class instead.
      */
     @Deprecated
     public void removeOnRoutingChangedListener(OnRoutingChangedListener listener) {
-        synchronized (mRoutingChangeListeners) {
-            if (mRoutingChangeListeners.containsKey(listener)) {
-                mRoutingChangeListeners.remove(listener);
-                testDisableNativeRoutingCallbacks();
-            }
-        }
+        removeOnRoutingChangedListener((AudioRouting.OnRoutingChangedListener) listener);
     }
 
     /**
-     * >= "N" Routing
-     * Helper class to handle the forwarding of native events to the appropriate listener
-     * (potentially) handled in a different thread
-     */
-    private class NativeNewRoutingEventHandlerDelegate {
-        private final Handler mHandler;
-
-        NativeNewRoutingEventHandlerDelegate(final AudioRecord record,
-                                   final AudioRouting.OnRoutingChangedListener listener,
-                                   Handler handler) {
-            // find the looper for our new event handler
-            Looper looper;
-            if (handler != null) {
-                looper = handler.getLooper();
-            } else {
-                // no given handler, use the looper the AudioRecord was created in
-                looper = mInitializationLooper;
-            }
-
-            // construct the event handler with this looper
-            if (looper != null) {
-                // implement the event handler delegate
-                mHandler = new Handler(looper) {
-                    @Override
-                    public void handleMessage(Message msg) {
-                        if (record == null) {
-                            return;
-                        }
-                        switch(msg.what) {
-                        case AudioSystem.NATIVE_EVENT_ROUTING_CHANGE:
-                            if (listener != null) {
-                                listener.onRoutingChanged(record);
-                            }
-                            break;
-                        default:
-                            loge("Unknown native event type: " + msg.what);
-                            break;
-                        }
-                    }
-                };
-            } else {
-                mHandler = null;
-            }
-        }
-
-        Handler getHandler() {
-            return mHandler;
-        }
-    }
-
-    /**
-     * Marshmallow Routing
      * Helper class to handle the forwarding of native events to the appropriate listener
      * (potentially) handled in a different thread
      */
@@ -1524,7 +1470,7 @@
         private final Handler mHandler;
 
         NativeRoutingEventHandlerDelegate(final AudioRecord record,
-                                   final OnRoutingChangedListener listener,
+                                   final AudioRouting.OnRoutingChangedListener listener,
                                    Handler handler) {
             // find the looper for our new event handler
             Looper looper;
@@ -1571,26 +1517,12 @@
      */
     private void broadcastRoutingChange() {
         AudioManager.resetAudioPortGeneration();
-        // Marshmallow Routing
-        Collection<NativeRoutingEventHandlerDelegate> values;
         synchronized (mRoutingChangeListeners) {
-            values = mRoutingChangeListeners.values();
-        }
-        for(NativeRoutingEventHandlerDelegate delegate : values) {
-            Handler handler = delegate.getHandler();
-            if (handler != null) {
-                handler.sendEmptyMessage(AudioSystem.NATIVE_EVENT_ROUTING_CHANGE);
-            }
-        }
-        // >= "N" Routing
-        Collection<NativeNewRoutingEventHandlerDelegate> newValues;
-        synchronized (mNewRoutingChangeListeners) {
-            newValues = mNewRoutingChangeListeners.values();
-        }
-        for(NativeNewRoutingEventHandlerDelegate delegate : newValues) {
-            Handler handler = delegate.getHandler();
-            if (handler != null) {
-                handler.sendEmptyMessage(AudioSystem.NATIVE_EVENT_ROUTING_CHANGE);
+            for (NativeRoutingEventHandlerDelegate delegate : mRoutingChangeListeners.values()) {
+                Handler handler = delegate.getHandler();
+                if (handler != null) {
+                    handler.sendEmptyMessage(AudioSystem.NATIVE_EVENT_ROUTING_CHANGE);
+                }
             }
         }
     }
@@ -1623,6 +1555,7 @@
      * @return true if successful, false if the specified {@link AudioDeviceInfo} is non-null and
      * does not correspond to a valid audio input device.
      */
+    @Override
     public boolean setPreferredDevice(AudioDeviceInfo deviceInfo) {
         // Do some validation....
         if (deviceInfo != null && !deviceInfo.isSource()) {
@@ -1643,6 +1576,7 @@
      * Returns the selected input specified by {@link #setPreferredDevice}. Note that this
      * is not guarenteed to correspond to the actual device being used for recording.
      */
+    @Override
     public AudioDeviceInfo getPreferredDevice() {
         synchronized (this) {
             return mPreferredDevice;
@@ -1683,7 +1617,6 @@
      * (potentially) handled in a different thread
      */
     private class NativeEventHandler extends Handler {
-
         private final AudioRecord mAudioRecord;
 
         NativeEventHandler(AudioRecord recorder, Looper looper) {
@@ -1714,8 +1647,7 @@
                 break;
             }
         }
-    };
-
+    }
 
     //---------------------------------------------------------
     // Java methods called from the native side
diff --git a/media/java/android/media/AudioRouting.java b/media/java/android/media/AudioRouting.java
index 41f92d4..26fa631 100644
--- a/media/java/android/media/AudioRouting.java
+++ b/media/java/android/media/AudioRouting.java
@@ -57,7 +57,7 @@
      * the callback. If <code>null</code>, the {@link Handler} associated with the main
      * {@link Looper} will be used.
      */
-    public void addOnRoutingListener(OnRoutingChangedListener listener,
+    public void addOnRoutingChangedListener(OnRoutingChangedListener listener,
             Handler handler);
 
     /**
@@ -66,7 +66,7 @@
      * @param listener The previously added {@link AudioRouting.OnRoutingChangedListener} interface
      * to remove.
      */
-    public void removeOnRoutingListener(OnRoutingChangedListener listener);
+    public void removeOnRoutingChangedListener(OnRoutingChangedListener listener);
 
     /**
      * Defines the interface by which applications can receive notifications of routing
diff --git a/media/java/android/media/AudioTrack.java b/media/java/android/media/AudioTrack.java
index 621129d..9d360db 100644
--- a/media/java/android/media/AudioTrack.java
+++ b/media/java/android/media/AudioTrack.java
@@ -40,6 +40,7 @@
 import android.util.ArrayMap;
 import android.util.Log;
 
+import com.android.internal.annotations.GuardedBy;
 import com.android.internal.app.IAppOpsService;
 
 /**
@@ -1489,6 +1490,7 @@
      * @deprecated Applications should use {@link #setVolume} instead, as it
      * more gracefully scales down to mono, and up to multi-channel content beyond stereo.
      */
+    @Deprecated
     public int setStereoVolume(float leftGain, float rightGain) {
         if (isRestricted()) {
             return SUCCESS;
@@ -2397,6 +2399,7 @@
      * @return true if succesful, false if the specified {@link AudioDeviceInfo} is non-null and
      * does not correspond to a valid audio output device.
      */
+    @Override
     public boolean setPreferredDevice(AudioDeviceInfo deviceInfo) {
         // Do some validation....
         if (deviceInfo != null && !deviceInfo.isSink()) {
@@ -2416,6 +2419,7 @@
      * Returns the selected output specified by {@link #setPreferredDevice}. Note that this
      * is not guaranteed to correspond to the actual device being used for playback.
      */
+    @Override
     public AudioDeviceInfo getPreferredDevice() {
         synchronized (this) {
             return mPreferredDevice;
@@ -2427,6 +2431,7 @@
      * Note: The query is only valid if the AudioTrack is currently playing. If it is not,
      * <code>getRoutedDevice()</code> will return null.
      */
+    @Override
     public AudioDeviceInfo getRoutedDevice() {
         int deviceId = native_getRoutedDeviceId();
         if (deviceId == 0) {
@@ -2445,8 +2450,8 @@
     /*
      * Call BEFORE adding a routing callback handler.
      */
-    private void testEnableNativeRoutingCallbacks() {
-        if (mRoutingChangeListeners.size() == 0 && mNewRoutingChangeListeners.size() == 0) {
+    private void testEnableNativeRoutingCallbacksLocked() {
+        if (mRoutingChangeListeners.size() == 0) {
             native_enableDeviceCallback();
         }
     }
@@ -2454,24 +2459,23 @@
     /*
      * Call AFTER removing a routing callback handler.
      */
-    private void testDisableNativeRoutingCallbacks() {
-        if (mRoutingChangeListeners.size() == 0 && mNewRoutingChangeListeners.size() == 0) {
+    private void testDisableNativeRoutingCallbacksLocked() {
+        if (mRoutingChangeListeners.size() == 0) {
             native_disableDeviceCallback();
         }
     }
 
     //--------------------------------------------------------------------------
-    // >= "N" (Re)Routing Info
+    // (Re)Routing Info
     //--------------------
     /**
      * The list of AudioRouting.OnRoutingChangedListener interfaces added (with
-     * {@link AudioTrack#addOnRoutingListener(AudioRouting.OnRoutingChangedListener,
-     *          android.os.Handler)}
-     * by an app to receive (re)routing notifications.
+     * {@link AudioRecord#addOnRoutingChangedListener} by an app to receive
+     * (re)routing notifications.
      */
-   private ArrayMap<AudioRouting.OnRoutingChangedListener, NativeNewRoutingEventHandlerDelegate>
-    mNewRoutingChangeListeners =
-        new ArrayMap<AudioRouting.OnRoutingChangedListener, NativeNewRoutingEventHandlerDelegate>();
+    @GuardedBy("mRoutingChangeListeners")
+    private ArrayMap<AudioRouting.OnRoutingChangedListener,
+            NativeRoutingEventHandlerDelegate> mRoutingChangeListeners = new ArrayMap<>();
 
    /**
     * Adds an {@link AudioRouting.OnRoutingChangedListener} to receive notifications of routing
@@ -2482,14 +2486,15 @@
     * the callback. If <code>null</code>, the {@link Handler} associated with the main
     * {@link Looper} will be used.
     */
-    public void addOnRoutingListener(AudioRouting.OnRoutingChangedListener listener,
+    @Override
+    public void addOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener,
             Handler handler) {
-        if (listener != null && !mNewRoutingChangeListeners.containsKey(listener)) {
-            synchronized (mNewRoutingChangeListeners) {
-                testEnableNativeRoutingCallbacks();
-                mNewRoutingChangeListeners.put(
-                    listener, new NativeNewRoutingEventHandlerDelegate(this, listener,
-                            handler != null ? handler : new Handler(mInitializationLooper)));
+        synchronized (mRoutingChangeListeners) {
+            if (listener != null && !mRoutingChangeListeners.containsKey(listener)) {
+                testEnableNativeRoutingCallbacksLocked();
+                mRoutingChangeListeners.put(
+                        listener, new NativeRoutingEventHandlerDelegate(this, listener,
+                                handler != null ? handler : new Handler(mInitializationLooper)));
             }
         }
     }
@@ -2500,39 +2505,42 @@
      * @param listener The previously added {@link AudioRouting.OnRoutingChangedListener} interface
      * to remove.
      */
-    public void removeOnRoutingListener(AudioRouting.OnRoutingChangedListener listener) {
-        if (mNewRoutingChangeListeners.containsKey(listener)) {
-            mNewRoutingChangeListeners.remove(listener);
+    @Override
+    public void removeOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener) {
+        synchronized (mRoutingChangeListeners) {
+            if (mRoutingChangeListeners.containsKey(listener)) {
+                mRoutingChangeListeners.remove(listener);
+            }
+            testDisableNativeRoutingCallbacksLocked();
         }
-        testDisableNativeRoutingCallbacks();
     }
 
     //--------------------------------------------------------------------------
-    // Marshmallow (Re)Routing Info
+    // (Re)Routing Info
     //--------------------
     /**
-     * Defines the interface by which applications can receive notifications of routing
-     * changes for the associated {@link AudioTrack}.
+     * Defines the interface by which applications can receive notifications of
+     * routing changes for the associated {@link AudioTrack}.
+     *
+     * @deprecated users should switch to the general purpose
+     *             {@link AudioRouting.OnRoutingChangedListener} class instead.
      */
     @Deprecated
-    public interface OnRoutingChangedListener {
+    public interface OnRoutingChangedListener extends AudioRouting.OnRoutingChangedListener {
         /**
-         * Called when the routing of an AudioTrack changes from either and explicit or
-         * policy rerouting.  Use {@link #getRoutedDevice()} to retrieve the newly routed-to
-         * device.
+         * Called when the routing of an AudioTrack changes from either and
+         * explicit or policy rerouting. Use {@link #getRoutedDevice()} to
+         * retrieve the newly routed-to device.
          */
-        @Deprecated
         public void onRoutingChanged(AudioTrack audioTrack);
-    }
 
-    /**
-     * The list of AudioTrack.OnRoutingChangedListener interfaces added (with
-     * {@link AudioTrack#addOnRoutingChangedListener(OnRoutingChangedListener, android.os.Handler)}
-     * by an app to receive (re)routing notifications.
-     */
-    private ArrayMap<OnRoutingChangedListener, NativeRoutingEventHandlerDelegate>
-        mRoutingChangeListeners =
-            new ArrayMap<OnRoutingChangedListener, NativeRoutingEventHandlerDelegate>();
+        @Override
+        default public void onRoutingChanged(AudioRouting router) {
+            if (router instanceof AudioTrack) {
+                onRoutingChanged((AudioTrack) router);
+            }
+        }
+    }
 
     /**
      * Adds an {@link OnRoutingChangedListener} to receive notifications of routing changes
@@ -2542,33 +2550,25 @@
      * @param handler  Specifies the {@link Handler} object for the thread on which to execute
      * the callback. If <code>null</code>, the {@link Handler} associated with the main
      * {@link Looper} will be used.
+     * @deprecated users should switch to the general purpose
+     *             {@link AudioRouting.OnRoutingChangedListener} class instead.
      */
     @Deprecated
     public void addOnRoutingChangedListener(OnRoutingChangedListener listener,
             android.os.Handler handler) {
-        if (listener != null && !mRoutingChangeListeners.containsKey(listener)) {
-            synchronized (mRoutingChangeListeners) {
-                testEnableNativeRoutingCallbacks();
-                mRoutingChangeListeners.put(
-                    listener, new NativeRoutingEventHandlerDelegate(this, listener,
-                            handler != null ? handler : new Handler(mInitializationLooper)));
-            }
-        }
+        addOnRoutingChangedListener((AudioRouting.OnRoutingChangedListener) listener, handler);
     }
 
     /**
      * Removes an {@link OnRoutingChangedListener} which has been previously added
      * to receive rerouting notifications.
      * @param listener The previously added {@link OnRoutingChangedListener} interface to remove.
+     * @deprecated users should switch to the general purpose
+     *             {@link AudioRouting.OnRoutingChangedListener} class instead.
      */
     @Deprecated
     public void removeOnRoutingChangedListener(OnRoutingChangedListener listener) {
-        synchronized (mRoutingChangeListeners) {
-            if (mRoutingChangeListeners.containsKey(listener)) {
-                mRoutingChangeListeners.remove(listener);
-            }
-            testDisableNativeRoutingCallbacks();
-        }
+        removeOnRoutingChangedListener((AudioRouting.OnRoutingChangedListener) listener);
     }
 
     /**
@@ -2576,27 +2576,12 @@
      */
     private void broadcastRoutingChange() {
         AudioManager.resetAudioPortGeneration();
-
-        // Marshmallow Routing
-        Collection<NativeRoutingEventHandlerDelegate> values;
         synchronized (mRoutingChangeListeners) {
-            values = mRoutingChangeListeners.values();
-        }
-        for(NativeRoutingEventHandlerDelegate delegate : values) {
-            Handler handler = delegate.getHandler();
-            if (handler != null) {
-                handler.sendEmptyMessage(AudioSystem.NATIVE_EVENT_ROUTING_CHANGE);
-            }
-        }
-        // >= "N" Routing
-        Collection<NativeNewRoutingEventHandlerDelegate> newValues;
-        synchronized (mNewRoutingChangeListeners) {
-            newValues = mNewRoutingChangeListeners.values();
-        }
-        for(NativeNewRoutingEventHandlerDelegate delegate : newValues) {
-            Handler handler = delegate.getHandler();
-            if (handler != null) {
-                handler.sendEmptyMessage(AudioSystem.NATIVE_EVENT_ROUTING_CHANGE);
+            for (NativeRoutingEventHandlerDelegate delegate : mRoutingChangeListeners.values()) {
+                Handler handler = delegate.getHandler();
+                if (handler != null) {
+                    handler.sendEmptyMessage(AudioSystem.NATIVE_EVENT_ROUTING_CHANGE);
+                }
             }
         }
     }
@@ -2681,7 +2666,6 @@
     }
 
     /**
-     * Marshmallow Routing API.
      * Helper class to handle the forwarding of native events to the appropriate listener
      * (potentially) handled in a different thread
      */
@@ -2689,57 +2673,6 @@
         private final Handler mHandler;
 
         NativeRoutingEventHandlerDelegate(final AudioTrack track,
-                                   final OnRoutingChangedListener listener,
-                                   Handler handler) {
-            // find the looper for our new event handler
-            Looper looper;
-            if (handler != null) {
-                looper = handler.getLooper();
-            } else {
-                // no given handler, use the looper the AudioTrack was created in
-                looper = mInitializationLooper;
-            }
-
-            // construct the event handler with this looper
-            if (looper != null) {
-                // implement the event handler delegate
-                mHandler = new Handler(looper) {
-                    @Override
-                    public void handleMessage(Message msg) {
-                        if (track == null) {
-                            return;
-                        }
-                        switch(msg.what) {
-                        case AudioSystem.NATIVE_EVENT_ROUTING_CHANGE:
-                            if (listener != null) {
-                                listener.onRoutingChanged(track);
-                            }
-                            break;
-                        default:
-                            loge("Unknown native event type: " + msg.what);
-                            break;
-                        }
-                    }
-                };
-            } else {
-                mHandler = null;
-            }
-        }
-
-        Handler getHandler() {
-            return mHandler;
-        }
-    }
-
-    /**
-     * Marshmallow Routing API.
-     * Helper class to handle the forwarding of native events to the appropriate listener
-     * (potentially) handled in a different thread
-     */
-    private class NativeNewRoutingEventHandlerDelegate {
-        private final Handler mHandler;
-
-        NativeNewRoutingEventHandlerDelegate(final AudioTrack track,
                                    final AudioRouting.OnRoutingChangedListener listener,
                                    Handler handler) {
             // find the looper for our new event handler