function paintCountIs(plugin, expected, msg) {
  var count = plugin.getPaintCount();
  var realExpected = expected;
  ++realExpected; // extra paint at startup for all async-rendering plugins
  ok(
    realExpected == count,
    msg +
      " (expected " +
      expected +
      " independent paints, expected " +
      realExpected +
      " logged paints, got " +
      count +
      " actual paints)"
  );
}

function getTestPlugin(pluginName) {
  var ph = SpecialPowers.Cc["@mozilla.org/plugin/host;1"].getService(
    SpecialPowers.Ci.nsIPluginHost
  );
  var tags = ph.getPluginTags();
  var name = pluginName || "Test Plug-in";
  for (var tag of tags) {
    if (tag.name == name) {
      return tag;
    }
  }

  ok(false, "Could not find plugin tag with plugin name '" + name + "'");
  return null;
}

// call this to set the test plugin(s) initially expected enabled state.
// it will automatically be reset to it's previous value after the test
// ends
function setTestPluginEnabledState(newEnabledState, pluginName) {
  var oldEnabledState = SpecialPowers.setTestPluginEnabledState(
    newEnabledState,
    pluginName
  );
  var plugin = getTestPlugin(pluginName);
  // Run a nested event loop to wait for the preference change to
  // propagate to the child. Yuck!
  SpecialPowers.Services.tm.spinEventLoopUntil(() => {
    return plugin.enabledState == newEnabledState;
  });
  SimpleTest.registerCleanupFunction(async function() {
    return SpecialPowers.setTestPluginEnabledState(
      await oldEnabledState,
      pluginName
    );
  });
}

function crashAndGetCrashServiceRecord(crashMethodName, callback) {
  var crashMan = SpecialPowers.Cu.import("resource://gre/modules/Services.jsm")
    .Services.crashmanager;

  // First, clear the crash record store.
  info("Waiting for pruneOldCrashes");
  var future = new Date(Date.now() + 1000 * 60 * 60 * 24);
  crashMan.pruneOldCrashes(future).then(
    function() {
      var iframe = document.getElementById("iframe1");
      var p = iframe.contentDocument.getElementById("plugin1");

      var crashDateMS = Date.now();
      try {
        p[crashMethodName]();
        ok(false, "p." + crashMethodName + "() should throw an exception");
      } catch (e) {
        ok(true, "p." + crashMethodName + "() should throw an exception");
      }

      // The crash record store is written and read back asyncly, so poll for
      // the new record.
      function tryGetCrash() {
        info("Waiting for getCrashes");
        crashMan.getCrashes().then(
          SpecialPowers.wrapCallback(function(crashes) {
            if (crashes.length) {
              is(crashes.length, 1, "There should be only one record");
              var crash = SpecialPowers.wrap(crashes[0]);
              ok(!!crash.id, "Record should have an ID");
              ok(!!crash.crashDate, "Record should have a crash date");
              var dateMS = crash.crashDate.valueOf();
              var twoMin = 1000 * 60 * 2;
              ok(
                crashDateMS - twoMin <= dateMS &&
                  dateMS <= crashDateMS + twoMin,
                "Record's crash date should be nowish: " +
                  "now=" +
                  crashDateMS +
                  " recordDate=" +
                  dateMS
              );
              callback(crashMan, crash);
            } else {
              setTimeout(tryGetCrash, 1000);
            }
          }),
          function(err) {
            ok(false, "Error getting crashes: " + err);
            SimpleTest.finish();
          }
        );
      }
      setTimeout(tryGetCrash, 1000);
    },
    function() {
      ok(false, "pruneOldCrashes error");
      SimpleTest.finish();
    }
  );
}

/**
 * Returns a promise which resolves on `mozFullScreenChange`.
 */
function promiseFullScreenChange() {
  return new Promise(resolve => {
    document.addEventListener(
      "fullscreenchange",
      function(e) {
        resolve();
      },
      { once: true }
    );
  });
}

/**
 * Crashes target plugin. Returns a promise; resolves on successful crash,
 * rejects otherwise.
 * @param plugin  Target plugin to attempt to crash.
 */
function crashPlugin(plugin) {
  return new Promise((resolve, reject) => {
    try {
      plugin.crash();
      reject();
    } catch (e) {
      resolve();
    }
  });
}