[Android] Introduce RegistrationPolicy for NetworkChangeNotifier.

net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java

Index: net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java
diff --git a/net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java b/net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java
index 466d03f194e83a9caa43a54e57062f09292d04b6..468a1b42c5de393bc565311f839a7614051a5a96 100644
--- a/net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java
+++ b/net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java
@@ -17,8 +17,6 @@ import android.net.wifi.WifiManager;
 import android.telephony.TelephonyManager;
 import android.util.Log;
 
-import org.chromium.base.ApplicationState;
-import org.chromium.base.ApplicationStatus;
 import org.chromium.base.VisibleForTesting;
 
 /**
@@ -26,9 +24,8 @@ import org.chromium.base.VisibleForTesting;
  * Note that use of this class requires that the app have the platform
  * ACCESS_NETWORK_STATE permission.
  */
-public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver
-        implements ApplicationStatus.ApplicationStateListener {
-
+public class NetworkChangeNotifierAutoDetect
+        extends BroadcastReceiver implements RegistrationPolicy.Listener {
     static class NetworkState {
         private final boolean mConnected;
         private final int mType;
@@ -139,15 +136,15 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver
 
     private static final String TAG = "NetworkChangeNotifierAutoDetect";
     private static final int UNKNOWN_LINK_SPEED = -1;
-    private final NetworkConnectivityIntentFilter mIntentFilter;
 
+    private final NetworkConnectivityIntentFilter mIntentFilter;
     private final Observer mObserver;
-
     private final Context mContext;
+    private final RegistrationPolicy mRegistrationPolicy;
+
     private ConnectivityManagerDelegate mConnectivityManagerDelegate;
     private WifiManagerDelegate mWifiManagerDelegate;
     private boolean mRegistered;
-    private final boolean mApplicationStateRegistered;
     private int mConnectionType;
     private String mWifiSSID;
     private double mMaxBandwidthMbps;
@@ -166,8 +163,8 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver
      * @param alwaysWatchForChanges If true, always watch for network changes.
      *    Otherwise, only watch if app is in foreground.
      */
-    public NetworkChangeNotifierAutoDetect(Observer observer, Context context,
-            boolean alwaysWatchForChanges) {
+    public NetworkChangeNotifierAutoDetect(
+            Observer observer, Context context, RegistrationPolicy policy) {
         mObserver = observer;
         mContext = context.getApplicationContext();
         mConnectivityManagerDelegate = new ConnectivityManagerDelegate(context);
@@ -178,15 +175,8 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver
         mMaxBandwidthMbps = getCurrentMaxBandwidthInMbps(networkState);
         mIntentFilter =
                 new NetworkConnectivityIntentFilter(mWifiManagerDelegate.getHasWifiPermission());
-
-        if (alwaysWatchForChanges) {
-            registerReceiver();
-            mApplicationStateRegistered = false;
-        } else {
-            ApplicationStatus.registerApplicationStateListener(this);
-            onApplicationStateChange(getApplicationState());
-            mApplicationStateRegistered = true;
-        }
+        mRegistrationPolicy = policy;
+        mRegistrationPolicy.init(this);
     }
 
     /**
@@ -203,13 +193,9 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver
         mWifiManagerDelegate = delegate;
     }
 
-    /**
-     * Returns the activity's status.
-     * @return an {@code int} that is one of {@code ApplicationState.HAS_*_ACTIVITIES}.
-     */
     @VisibleForTesting
-    int getApplicationState() {
-        return ApplicationStatus.getStateForApplication();
+    RegistrationPolicy getRegistrationPolicy() {
+        return mRegistrationPolicy;
     }
 
     /**
@@ -221,28 +207,8 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver
     }
 
     public void destroy() {
-        if (mApplicationStateRegistered) ApplicationStatus.unregisterApplicationStateListener(this);
-        unregisterReceiver();
-    }
-
-    /**
-     * Register a BroadcastReceiver in the given context.
-     */
-    private void registerReceiver() {
-        if (!mRegistered) {
-            mRegistered = true;
-            mContext.registerReceiver(this, mIntentFilter);
-        }
-    }
-
-    /**
-     * Unregister the BroadcastReceiver in the given context.
-     */
-    private void unregisterReceiver() {
-        if (mRegistered) {
-            mRegistered = false;
-            mContext.unregisterReceiver(this);
-        }
+        mRegistrationPolicy.destroy();
+        unregister();
     }
 
     public NetworkState getCurrentNetworkState() {
@@ -379,17 +345,23 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver
         }
     }
 
-    // ApplicationStatus.ApplicationStateListener
+    // RegistrationPolicy.Listener
     @Override
-    public void onApplicationStateChange(int newState) {
+    public void register() {
+        if (mRegistered) return;
+
         final NetworkState networkState = getCurrentNetworkState();
-        if (newState == ApplicationState.HAS_RUNNING_ACTIVITIES) {
-            connectionTypeChanged(networkState);
-            maxBandwidthChanged(networkState);
-            registerReceiver();
-        } else if (newState == ApplicationState.HAS_PAUSED_ACTIVITIES) {
-            unregisterReceiver();
-        }
+        connectionTypeChanged(networkState);
+        maxBandwidthChanged(networkState);
+        mContext.registerReceiver(this, mIntentFilter);
+        mRegistered = true;
+    }
+
+    @Override
+    public void unregister() {
+        if (!mRegistered) return;
+        mContext.unregisterReceiver(this);
+        mRegistered = false;
     }
 
     private void connectionTypeChanged(NetworkState networkState) {