Merge "Fix waitForLooperDone()" into main

import android.os.MessageQueue;

import android.util.Log;

import com.android.internal.annotations.GuardedBy;

import com.android.ravenwood.common.SneakyThrow;

import java.util.HashMap;

import java.util.Map;

import java.util.concurrent.Callable;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.TimeUnit;

    private static final int DEFAULT_TIMEOUT_SECONDS = 10;

    private class MainHandlerHolder {

        static Handler sMainHandler = new Handler(Looper.getMainLooper());

    @GuardedBy("sHandlers")

    private static final Map<Looper, Handler> sHandlers = new HashMap<>();

    /**

     * Return a handler for any looper.

     */

    @NonNull

    private static Handler getHandler(@NonNull Looper looper) {

        synchronized (sHandlers) {

            return sHandlers.computeIfAbsent(looper, (l) -> new Handler(l));

        }

    }

    /**

     * Returns the main thread handler.

     */

    public static Handler getMainHandler() {

        return MainHandlerHolder.sMainHandler;

        return getHandler(Looper.getMainLooper());

    }

    /**

    public static void waitForLooperDone(Looper looper) {

        var idler = new Idler();

        looper.getQueue().addIdleHandler(idler);

        // Wake up the queue, if sleeping.

        getHandler(looper).post(() -> {});

        idler.waitForIdle();

        sPendingExceptionThrower.run();