Bug 1290467 - part5 : change service's life time. r=sebastian

Now the life time of the MediaControlService would be as same as the Fennec app.
To make code flow more easily, requesting/abandoning the audio focus wouldn't
affect the media control.

We would mainly communicate with the media control via TabEvents.

MozReview-Commit-ID: KT59bII0HuN

--HG--
extra : rebase_source : d8f2c810f24ef6ea72a274db2b432ca8f8876d8e

mobile/android/base/java/org/mozilla/gecko/media/AudioFocusAgent.java

@@ -78,6 +78,7 @@ public class AudioFocusAgent {
                 }
             }
         };
+        notifyMediaControlService(MediaControlService.ACTION_INIT);
     }
 
     @RobocopTarget
@@ -113,7 +114,6 @@ public class AudioFocusAgent {
         Log.d(LOGTAG, focusMsg);
         if (result == AudioManager.AUDIOFOCUS_GAIN) {
             mAudioFocusState = OWN_FOCUS;
-            notifyMediaControlService(MediaControlService.ACTION_START);
         }
     }
 
@@ -125,7 +125,6 @@ public class AudioFocusAgent {
         Log.d(LOGTAG, "Abandon AudioFocus");
         mAudioManager.abandonAudioFocus(mAfChangeListener);
         mAudioFocusState = LOST_FOCUS;
-        notifyMediaControlService(MediaControlService.ACTION_STOP);
     }
 
     private void notifyMediaControlService(String action) {

mobile/android/base/java/org/mozilla/gecko/media/MediaControlService.java

@@ -32,6 +32,7 @@ import java.lang.ref.WeakReference;
 public class MediaControlService extends Service implements Tabs.OnTabsChangedListener {
     private static final String LOGTAG = "MediaControlService";
 
+    public static final String ACTION_INIT           = "action_init";
     public static final String ACTION_START          = "action_start";
     public static final String ACTION_PLAY           = "action_play";
     public static final String ACTION_PAUSE          = "action_pause";
@@ -155,6 +156,10 @@ public class MediaControlService extends Service implements Tabs.OnTabsChangedLi
 
         Log.d(LOGTAG, "HandleIntent, action = " + intent.getAction() + ", actionState = " + mActionState);
         switch (intent.getAction()) {
+            case ACTION_INIT :
+                // This action is used to create a service and do the initialization,
+                // the actual operation would be executed via tab events.
+                break;
             case ACTION_START :
                 mController.getTransportControls().sendCustomAction(ACTION_START, null);
                 break;
@@ -248,7 +253,6 @@ public class MediaControlService extends Service implements Tabs.OnTabsChangedLi
                 notifyObservers("MediaControl", "mediaControlStopped");
                 mActionState = ACTION_STOP;
                 mTabReference = new WeakReference<>(null);
-                stopSelf();
             }
         });
     }
@@ -270,6 +274,7 @@ public class MediaControlService extends Service implements Tabs.OnTabsChangedLi
         Log.d(LOGTAG, "notifyControlInterfaceChanged, action = " + action);
 
         if (isNeedToRemoveControlInterface(action)) {
+            stopForeground(false);
             NotificationManagerCompat.from(this).cancel(MEDIA_CONTROL_ID);
             return;
         }