Add speaker on/off control on Android for WebRTC

media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java

Index: media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java
===================================================================
--- media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java	(revision 189667)
+++ media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java	(working copy)
@@ -4,7 +4,10 @@
 
 package org.chromium.media;
 
+import android.content.BroadcastReceiver;
 import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
 import android.media.AudioManager;
 
 import org.chromium.base.CalledByNative;
@@ -12,12 +15,54 @@
 
 @JNINamespace("media")
 class AudioManagerAndroid {
+    private static final String TAG = AudioManagerAndroid.class.getSimpleName();
+
+    private final AudioManager mAudioManager;
+    private final Context mContext;
+
+    private BroadcastReceiver mReceiver;
+    private boolean mOriginalSpeakerStatus;
+
     @CalledByNative
-    public static void setMode(Context context, int mode) {
-        AudioManager audioManager =
-                (AudioManager)context.getSystemService(Context.AUDIO_SERVICE);
-        if (null != audioManager) {
-            audioManager.setMode(mode);
+    public void setMode(int mode) {
+        mAudioManager.setMode(mode);
+    }
+
+    @CalledByNative
+    private static AudioManagerAndroid createAudioManagerAndroid(Context context) {
+        return new AudioManagerAndroid(context);
+    }
+
+    private AudioManagerAndroid(Context context) {
+        mContext = context;
+        mAudioManager = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE);
+    }
+
+    @CalledByNative
+    public void registerHeadsetReceiver() {
+        if (mReceiver != null) {
+            return;
         }
+
+        mOriginalSpeakerStatus = mAudioManager.isSpeakerphoneOn();
+        IntentFilter filter = new IntentFilter(Intent.ACTION_HEADSET_PLUG);
+
+        mReceiver = new BroadcastReceiver() {
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                if (Intent.ACTION_HEADSET_PLUG.equals(intent.getAction())) {
+                    mAudioManager.setSpeakerphoneOn(
+                            intent.getIntExtra("state", 0) == 0);
+                }
+            }
+        };
+        mContext.registerReceiver(mReceiver, filter);
     }
+
+    @CalledByNative
+    public void unregisterHeadsetReceiver() {
+        mContext.unregisterReceiver(mReceiver);
+        mReceiver = null;
+        mAudioManager.setSpeakerphoneOn(mOriginalSpeakerStatus);
+    }
 }