Fix some memory leaks.

Fixes #3224
Closes #3228
// FREEBIE

src/org/thoughtcrime/securesms/recipients/Recipient.java

@@ -17,7 +17,6 @@
 package org.thoughtcrime.securesms.recipients;
 
 import android.content.Context;
-import android.graphics.Bitmap;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.util.Log;
@@ -28,13 +27,16 @@ import org.thoughtcrime.securesms.util.FutureTaskListener;
 import org.thoughtcrime.securesms.util.GroupUtil;
 import org.thoughtcrime.securesms.util.ListenableFutureTask;
 
+import java.util.Collections;
 import java.util.HashSet;
+import java.util.Set;
+import java.util.WeakHashMap;
 
 public class Recipient {
 
   private final static String TAG = Recipient.class.getSimpleName();
 
-  private final HashSet<RecipientModifiedListener> listeners = new HashSet<>();
+  private final Set<RecipientModifiedListener> listeners = Collections.newSetFromMap(new WeakHashMap<RecipientModifiedListener, Boolean>());
 
   private final long recipientId;
 
@@ -55,7 +57,7 @@ public class Recipient {
       @Override
       public void onSuccess(RecipientDetails result) {
         if (result != null) {
-          HashSet<RecipientModifiedListener> localListeners;
+          Set<RecipientModifiedListener> localListeners;
 
           synchronized (Recipient.this) {
             Recipient.this.name                      = result.name;
@@ -63,7 +65,7 @@ public class Recipient {
             Recipient.this.contactUri                = result.contactUri;
             Recipient.this.contactPhoto              = result.avatar;
 
-            localListeners                           = (HashSet<RecipientModifiedListener>) listeners.clone();
+            localListeners                           = new HashSet<>(listeners);
             listeners.clear();
           }
 
@@ -115,18 +117,6 @@ public class Recipient {
     listeners.remove(listener);
   }
 
-  public void notifyListeners() {
-    HashSet<RecipientModifiedListener> localListeners;
-
-    synchronized (this) {
-      localListeners = (HashSet<RecipientModifiedListener>)listeners.clone();
-    }
-
-    for (RecipientModifiedListener listener : localListeners) {
-      listener.onModified(this);
-    }
-  }
-
   public synchronized String toShortString() {
     return (name == null ? number : name);
   }

src/org/thoughtcrime/securesms/service/ApplicationMigrationService.java

@@ -23,9 +23,11 @@ import org.thoughtcrime.securesms.crypto.MasterSecret;
 import org.thoughtcrime.securesms.database.SmsMigrator;
 import org.thoughtcrime.securesms.database.SmsMigrator.ProgressDescription;
 
+import java.lang.ref.WeakReference;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
 
+// FIXME: This class is nuts.
 public class ApplicationMigrationService extends Service
     implements SmsMigrator.SmsMigrationProgressListener
 {
@@ -39,9 +41,9 @@ public class ApplicationMigrationService extends Service
   private final Binder binder                       = new ApplicationMigrationBinder();
   private final Executor executor                   = Executors.newSingleThreadExecutor();
 
-  private Handler handler                         = null;
+  private WeakReference<Handler>     handler      = null;
   private NotificationCompat.Builder notification = null;
-  private ImportState state                       = new ImportState(ImportState.STATE_IDLE, null);
+  private ImportState                state        = new ImportState(ImportState.STATE_IDLE, null);
 
   @Override
   public void onCreate() {
@@ -70,7 +72,7 @@ public class ApplicationMigrationService extends Service
   }
 
   public void setImportStateHandler(Handler handler) {
-    this.handler = handler;
+    this.handler = new WeakReference<>(handler);
   }
 
   private void registerCompletedReceiver() {
@@ -103,6 +105,8 @@ public class ApplicationMigrationService extends Service
   private void setState(ImportState state) {
     this.state = state;
 
+    Handler handler = this.handler.get();
+
     if (handler != null) {
       handler.obtainMessage(state.state, state.progress).sendToTarget();
     }

src/org/thoughtcrime/securesms/service/RegistrationService.java

@@ -21,7 +21,6 @@ import org.thoughtcrime.securesms.jobs.GcmRefreshJob;
 import org.thoughtcrime.securesms.push.TextSecureCommunicationFactory;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientFactory;
-import org.thoughtcrime.securesms.recipients.RecipientFormattingException;
 import org.thoughtcrime.securesms.util.DirectoryHelper;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.thoughtcrime.securesms.util.Util;
@@ -34,6 +33,7 @@ import org.whispersystems.textsecure.api.TextSecureAccountManager;
 import org.whispersystems.textsecure.api.push.exceptions.ExpectationFailedException;
 
 import java.io.IOException;
+import java.lang.ref.WeakReference;
 import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -77,7 +77,7 @@ public class RegistrationService extends Service {
 
   private volatile RegistrationState registrationState = new RegistrationState(RegistrationState.STATE_IDLE);
 
-  private volatile Handler                 registrationStateHandler;
+  private volatile WeakReference<Handler>  registrationStateHandler;
   private volatile ChallengeReceiver       challengeReceiver;
   private          String                  challenge;
   private          long                    verificationStartTime;
@@ -298,6 +298,8 @@ public class RegistrationService extends Service {
   private void setState(RegistrationState state) {
     this.registrationState = state;
 
+    Handler registrationStateHandler = this.registrationStateHandler.get();
+
     if (registrationStateHandler != null) {
       registrationStateHandler.obtainMessage(state.state, state).sendToTarget();
     }
@@ -319,7 +321,7 @@ public class RegistrationService extends Service {
   }
 
   public void setRegistrationStateHandler(Handler registrationStateHandler) {
-    this.registrationStateHandler = registrationStateHandler;
+    this.registrationStateHandler = new WeakReference<>(registrationStateHandler);
   }
 
   public class RegistrationServiceBinder extends Binder {