Merge "Use thread-safe collection for storing listeners" into main

import com.android.systemui.plugins.FalsingManager;

import com.android.systemui.util.time.SystemClock;

import java.util.ArrayList;

import com.google.common.collect.Sets;

import java.util.Collection;

import java.util.List;

import java.util.Set;

import java.util.concurrent.DelayQueue;

import java.util.concurrent.Delayed;

import java.util.concurrent.TimeUnit;

    private final SystemClock mSystemClock;

    DelayQueue<CombinedResult> mResults = new DelayQueue<>();

    private final List<BeliefListener> mBeliefListeners = new ArrayList<>();

    private final Set<BeliefListener> mBeliefListeners = Sets.newConcurrentHashSet();

    @Inject

    HistoryTracker(SystemClock systemClock) {

    }

    void addBeliefListener(BeliefListener listener) {

        if (listener != null) {

            mBeliefListeners.add(listener);

        }

    }

    void removeBeliefListener(BeliefListener listener) {

        if (listener != null) {

            mBeliefListeners.remove(listener);

        }

    }

    /**

     * Represents a falsing score combing all the classifiers together.

     *