Fix wakelock release exception.

app/src/main/java/org/thoughtcrime/securesms/notifications/DefaultMessageNotifier.java

@@ -109,6 +109,11 @@ public class DefaultMessageNotifier implements MessageNotifier {
     visibleThread = threadId;
   }
 
+  @Override
+  public long getVisibleThread() {
+    return visibleThread;
+  }
+
   @Override
   public void clearVisibleThread() {
     setVisibleThread(-1);

app/src/main/java/org/thoughtcrime/securesms/notifications/MessageNotifier.java

@@ -12,6 +12,7 @@ import org.thoughtcrime.securesms.util.concurrent.SignalExecutors;
 
 public interface MessageNotifier {
   void setVisibleThread(long threadId);
+  long getVisibleThread();
   void clearVisibleThread();
   void setLastDesktopActivityTimestamp(long timestamp);
   void notifyMessageDeliveryFailed(Context context, Recipient recipient, long threadId);

app/src/main/java/org/thoughtcrime/securesms/notifications/OptimizedMessageNotifier.java

@@ -30,6 +30,11 @@ public class OptimizedMessageNotifier implements MessageNotifier {
     wrapped.setVisibleThread(threadId);
   }
 
+  @Override
+  public long getVisibleThread() {
+    return wrapped.getVisibleThread();
+  }
+
   @Override
   public void clearVisibleThread() {
     wrapped.clearVisibleThread();