Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

34 files changed, 6715 insertions, 0 deletions

diff --git a/testing/web-platform/tests/resources/chromium/README.md b/testing/web-platform/tests/resources/chromium/README.md
new file mode 100644
index 0000000000..be090b332f
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/README.md
@@ -0,0 +1,7 @@
+This directory contains Chromium-specific test resources, including mocks for
+test-only APIs implemented with
+[MojoJS](https://chromium.googlesource.com/chromium/src/+/main/mojo/public/js/README.md).
+
+Please do **not** copy `*.mojom.m.js` into this directory. Follow this doc if you
+want to add new MojoJS-backed mocks:
+https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md#mojojs
diff --git a/testing/web-platform/tests/resources/chromium/contacts_manager_mock.js b/testing/web-platform/tests/resources/chromium/contacts_manager_mock.js
new file mode 100644
index 0000000000..049685242b
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/contacts_manager_mock.js
@@ -0,0 +1,90 @@
+// Copyright 2018 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import {ContactsManager, ContactsManagerReceiver} from '/gen/third_party/blink/public/mojom/contacts/contacts_manager.mojom.m.js';
+
+self.WebContactsTest = (() => {
+  class MockContacts {
+    constructor() {
+      this.receiver_ = new ContactsManagerReceiver(this);
+
+      this.interceptor_ =
+          new MojoInterfaceInterceptor(ContactsManager.$interfaceName);
+      this.interceptor_.oninterfacerequest =
+          e => this.receiver_.$.bindHandle(e.handle);
+      this.interceptor_.start();
+
+      this.selectedContacts_ = [];
+    }
+
+    formatAddress_(address) {
+      // These are all required fields in the mojo definition.
+      return {
+        country: address.country || '',
+        addressLine: address.addressLine || [],
+        region: address.region || '',
+        city: address.city || '',
+        dependentLocality: address.dependentLocality || '',
+        postalCode: address.postCode || '',
+        sortingCode: address.sortingCode || '',
+        organization: address.organization || '',
+        recipient: address.recipient || '',
+        phone: address.phone || '',
+      };
+    }
+
+    async select(multiple, includeNames, includeEmails, includeTel, includeAddresses, includeIcons) {
+      if (this.selectedContacts_ === null)
+        return {contacts: null};
+
+      const contactInfos = await Promise.all(this.selectedContacts_.map(async contact => {
+        const contactInfo = {};
+        if (includeNames)
+          contactInfo.name = contact.name || [];
+        if (includeEmails)
+          contactInfo.email = contact.email || [];
+        if (includeTel)
+          contactInfo.tel = contact.tel || [];
+        if (includeAddresses) {
+          contactInfo.address = (contact.address || []).map(address => this.formatAddress_(address));
+        }
+        if (includeIcons) {
+          contactInfo.icon = await Promise.all(
+            (contact.icon || []).map(async blob => ({
+              mimeType: blob.type,
+              data: (await blob.text()).split('').map(s => s.charCodeAt(0)),
+            })));
+        }
+        return contactInfo;
+      }));
+
+      if (!contactInfos.length) return {contacts: []};
+      if (!multiple) return {contacts: [contactInfos[0]]};
+      return {contacts: contactInfos};
+    }
+
+    setSelectedContacts(contacts) {
+      this.selectedContacts_ = contacts;
+    }
+
+    reset() {
+      this.receiver_.$.close();
+      this.interceptor_.stop();
+    }
+  }
+
+  const mockContacts = new MockContacts();
+
+  class ContactsTestChromium {
+    constructor() {
+      Object.freeze(this); // Make it immutable.
+    }
+
+    setSelectedContacts(contacts) {
+      mockContacts.setSelectedContacts(contacts);
+    }
+  }
+
+  return ContactsTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/content-index-helpers.js b/testing/web-platform/tests/resources/chromium/content-index-helpers.js
new file mode 100644
index 0000000000..936fe84c9b
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/content-index-helpers.js
@@ -0,0 +1,9 @@
+import {ContentIndexService} from '/gen/third_party/blink/public/mojom/content_index/content_index.mojom.m.js';
+
+// Returns a promise if the chromium based browser fetches icons for
+// content-index.
+export async function fetchesIcons() {
+  const remote = ContentIndexService.getRemote();
+  const {iconSizes} = await remote.getIconSizes();
+  return iconSizes.length > 0;
+};
diff --git a/testing/web-platform/tests/resources/chromium/enable-hyperlink-auditing.js b/testing/web-platform/tests/resources/chromium/enable-hyperlink-auditing.js
new file mode 100644
index 0000000000..263f6512f0
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/enable-hyperlink-auditing.js
@@ -0,0 +1,2 @@
+if (window.testRunner)
+  testRunner.overridePreference("WebKitHyperlinkAuditingEnabled", 1);
diff --git a/testing/web-platform/tests/resources/chromium/fake-hid.js b/testing/web-platform/tests/resources/chromium/fake-hid.js
new file mode 100644
index 0000000000..70a01490d8
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/fake-hid.js
@@ -0,0 +1,297 @@
+import {HidConnectionReceiver, HidDeviceInfo} from '/gen/services/device/public/mojom/hid.mojom.m.js';
+import {HidService, HidServiceReceiver} from '/gen/third_party/blink/public/mojom/hid/hid.mojom.m.js';
+
+// Fake implementation of device.mojom.HidConnection. HidConnection represents
+// an open connection to a HID device and can be used to send and receive
+// reports.
+class FakeHidConnection {
+  constructor(client) {
+    this.client_ = client;
+    this.receiver_ = new HidConnectionReceiver(this);
+    this.expectedWrites_ = [];
+    this.expectedGetFeatureReports_ = [];
+    this.expectedSendFeatureReports_ = [];
+  }
+
+  bindNewPipeAndPassRemote() {
+    return this.receiver_.$.bindNewPipeAndPassRemote();
+  }
+
+  // Simulate an input report sent from the device to the host. The connection
+  // client's onInputReport method will be called with the provided |reportId|
+  // and |buffer|.
+  simulateInputReport(reportId, reportData) {
+    if (this.client_) {
+      this.client_.onInputReport(reportId, reportData);
+    }
+  }
+
+  // Specify the result for an expected call to write. If |success| is true the
+  // write will be successful, otherwise it will simulate a failure. The
+  // parameters of the next write call must match |reportId| and |buffer|.
+  queueExpectedWrite(success, reportId, reportData) {
+    this.expectedWrites_.push({
+      params: {reportId, data: reportData},
+      result: {success},
+    });
+  }
+
+  // Specify the result for an expected call to getFeatureReport. If |success|
+  // is true the operation is successful, otherwise it will simulate a failure.
+  // The parameter of the next getFeatureReport call must match |reportId|.
+  queueExpectedGetFeatureReport(success, reportId, reportData) {
+    this.expectedGetFeatureReports_.push({
+      params: {reportId},
+      result: {success, buffer: reportData},
+    });
+  }
+
+  // Specify the result for an expected call to sendFeatureReport. If |success|
+  // is true the operation is successful, otherwise it will simulate a failure.
+  // The parameters of the next sendFeatureReport call must match |reportId| and
+  // |buffer|.
+  queueExpectedSendFeatureReport(success, reportId, reportData) {
+    this.expectedSendFeatureReports_.push({
+      params: {reportId, data: reportData},
+      result: {success},
+    });
+  }
+
+  // Asserts that there are no more expected operations.
+  assertExpectationsMet() {
+    assert_equals(this.expectedWrites_.length, 0);
+    assert_equals(this.expectedGetFeatureReports_.length, 0);
+    assert_equals(this.expectedSendFeatureReports_.length, 0);
+  }
+
+  read() {}
+
+  // Implementation of HidConnection::Write. Causes an assertion failure if
+  // there are no expected write operations, or if the parameters do not match
+  // the expected call.
+  async write(reportId, buffer) {
+    let expectedWrite = this.expectedWrites_.shift();
+    assert_not_equals(expectedWrite, undefined);
+    assert_equals(reportId, expectedWrite.params.reportId);
+    let actual = new Uint8Array(buffer);
+    compareDataViews(
+        new DataView(actual.buffer, actual.byteOffset),
+        new DataView(
+            expectedWrite.params.data.buffer,
+            expectedWrite.params.data.byteOffset));
+    return expectedWrite.result;
+  }
+
+  // Implementation of HidConnection::GetFeatureReport. Causes an assertion
+  // failure if there are no expected write operations, or if the parameters do
+  // not match the expected call.
+  async getFeatureReport(reportId) {
+    let expectedGetFeatureReport = this.expectedGetFeatureReports_.shift();
+    assert_not_equals(expectedGetFeatureReport, undefined);
+    assert_equals(reportId, expectedGetFeatureReport.params.reportId);
+    return expectedGetFeatureReport.result;
+  }
+
+  // Implementation of HidConnection::SendFeatureReport. Causes an assertion
+  // failure if there are no expected write operations, or if the parameters do
+  // not match the expected call.
+  async sendFeatureReport(reportId, buffer) {
+    let expectedSendFeatureReport = this.expectedSendFeatureReports_.shift();
+    assert_not_equals(expectedSendFeatureReport, undefined);
+    assert_equals(reportId, expectedSendFeatureReport.params.reportId);
+    let actual = new Uint8Array(buffer);
+    compareDataViews(
+        new DataView(actual.buffer, actual.byteOffset),
+        new DataView(
+            expectedSendFeatureReport.params.data.buffer,
+            expectedSendFeatureReport.params.data.byteOffset));
+    return expectedSendFeatureReport.result;
+  }
+}
+
+
+// A fake implementation of the HidService mojo interface. HidService manages
+// HID device access for clients in the render process. Typically, when a client
+// requests access to a HID device a chooser dialog is shown with a list of
+// available HID devices. Selecting a device from the chooser also grants
+// permission for the client to access that device.
+//
+// The fake implementation allows tests to simulate connected devices. It also
+// skips the chooser dialog and instead allows tests to specify which device
+// should be selected. All devices are treated as if the user had already
+// granted permission. It is possible to revoke permission with forget() later.
+class FakeHidService {
+  constructor() {
+    this.interceptor_ = new MojoInterfaceInterceptor(HidService.$interfaceName);
+    this.interceptor_.oninterfacerequest = e => this.bind(e.handle);
+    this.receiver_ = new HidServiceReceiver(this);
+    this.nextGuidValue_ = 0;
+    this.simulateConnectFailure_ = false;
+    this.reset();
+  }
+
+  start() {
+    this.interceptor_.start();
+  }
+
+  stop() {
+    this.interceptor_.stop();
+  }
+
+  reset() {
+    this.devices_ = new Map();
+    this.allowedDevices_ = new Map();
+    this.fakeConnections_ = new Map();
+    this.selectedDevices_ = [];
+  }
+
+  // Creates and returns a HidDeviceInfo with the specified device IDs.
+  makeDevice(vendorId, productId) {
+    let guidValue = ++this.nextGuidValue_;
+    let info = new HidDeviceInfo();
+    info.guid = 'guid-' + guidValue.toString();
+    info.physicalDeviceId = 'physical-device-id-' + guidValue.toString();
+    info.vendorId = vendorId;
+    info.productId = productId;
+    info.productName = 'product name';
+    info.serialNumber = '0';
+    info.reportDescriptor = new Uint8Array();
+    info.collections = [];
+    info.deviceNode = 'device node';
+    return info;
+  }
+
+  // Simulates a connected device the client has already been granted permission
+  // to. Returns the key used to store the device in the map. The key is either
+  // the physical device ID, or the device GUID if it has no physical device ID.
+  addDevice(deviceInfo, grantPermission = true) {
+    let key = deviceInfo.physicalDeviceId;
+    if (key.length === 0)
+      key = deviceInfo.guid;
+
+    let devices = this.devices_.get(key) || [];
+    devices.push(deviceInfo);
+    this.devices_.set(key, devices);
+
+    if (grantPermission) {
+      let allowedDevices = this.allowedDevices_.get(key) || [];
+      allowedDevices.push(deviceInfo);
+      this.allowedDevices_.set(key, allowedDevices);
+    }
+
+    if (this.client_)
+      this.client_.deviceAdded(deviceInfo);
+    return key;
+  }
+
+  // Simulates disconnecting a connected device.
+  removeDevice(key) {
+    let devices = this.devices_.get(key);
+    this.devices_.delete(key);
+    if (this.client_ && devices) {
+      devices.forEach(deviceInfo => {
+        this.client_.deviceRemoved(deviceInfo);
+      });
+    }
+  }
+
+  // Simulates updating the device information for a connected device.
+  changeDevice(deviceInfo) {
+    let key = deviceInfo.physicalDeviceId;
+    if (key.length === 0)
+      key = deviceInfo.guid;
+
+    let devices = this.devices_.get(key) || [];
+    let i = devices.length;
+    while (i--) {
+      if (devices[i].guid == deviceInfo.guid)
+        devices.splice(i, 1);
+    }
+    devices.push(deviceInfo);
+    this.devices_.set(key, devices);
+
+    let allowedDevices = this.allowedDevices_.get(key) || [];
+    let j = allowedDevices.length;
+    while (j--) {
+      if (allowedDevices[j].guid == deviceInfo.guid)
+        allowedDevices.splice(j, 1);
+    }
+    allowedDevices.push(deviceInfo);
+    this.allowedDevices_.set(key, allowedDevices);
+
+    if (this.client_)
+      this.client_.deviceChanged(deviceInfo);
+    return key;
+  }
+
+  // Sets a flag that causes the next call to connect() to fail.
+  simulateConnectFailure() {
+    this.simulateConnectFailure_ = true;
+  }
+
+  // Sets the key of the device that will be returned as the selected item the
+  // next time requestDevice is called. The device with this key must have been
+  // previously added with addDevice.
+  setSelectedDevice(key) {
+    this.selectedDevices_ = this.devices_.get(key);
+  }
+
+  // Returns the fake HidConnection object for this device, if there is one. A
+  // connection is created once the device is opened.
+  getFakeConnection(guid) {
+    return this.fakeConnections_.get(guid);
+  }
+
+  bind(handle) {
+    this.receiver_.$.bindHandle(handle);
+  }
+
+  registerClient(client) {
+    this.client_ = client;
+  }
+
+  // Returns an array of connected devices the client has already been granted
+  // permission to access.
+  async getDevices() {
+    let devices = [];
+    this.allowedDevices_.forEach((value) => {
+      devices = devices.concat(value);
+    });
+    return {devices};
+  }
+
+  // Simulates a device chooser prompt, returning |selectedDevices_| as the
+  // simulated selection. |options| is ignored.
+  async requestDevice(options) {
+    return {devices: this.selectedDevices_};
+  }
+
+  // Returns a fake connection to the device with the specified GUID. If
+  // |connectionClient| is not null, its onInputReport method will be called
+  // when input reports are received. If simulateConnectFailure() was called
+  // then a null connection is returned instead, indicating failure.
+  async connect(guid, connectionClient) {
+    if (this.simulateConnectFailure_) {
+      this.simulateConnectFailure_ = false;
+      return {connection: null};
+    }
+    const fakeConnection = new FakeHidConnection(connectionClient);
+    this.fakeConnections_.set(guid, fakeConnection);
+    return {connection: fakeConnection.bindNewPipeAndPassRemote()};
+  }
+
+  // Removes the allowed device.
+  async forget(deviceInfo) {
+    for (const [key, value] of this.allowedDevices_) {
+      for (const device of value) {
+        if (device.guid == deviceInfo.guid) {
+          this.allowedDevices_.delete(key);
+          break;
+        }
+      }
+    }
+    return {success: true};
+  }
+}
+
+export const fakeHidService = new FakeHidService();
diff --git a/testing/web-platform/tests/resources/chromium/fake-serial.js b/testing/web-platform/tests/resources/chromium/fake-serial.js
new file mode 100644
index 0000000000..e1e4d57e3e
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/fake-serial.js
@@ -0,0 +1,443 @@
+import {SerialPortFlushMode, SerialPortRemote, SerialReceiveError, SerialPortReceiver, SerialSendError} from '/gen/services/device/public/mojom/serial.mojom.m.js';
+import {SerialService, SerialServiceReceiver} from '/gen/third_party/blink/public/mojom/serial/serial.mojom.m.js';
+
+// Implementation of an UnderlyingSource to create a ReadableStream from a Mojo
+// data pipe consumer handle.
+class DataPipeSource {
+  constructor(consumer) {
+    this.consumer_ = consumer;
+  }
+
+  async pull(controller) {
+    let chunk = new ArrayBuffer(64);
+    let {result, numBytes} = this.consumer_.readData(chunk);
+    if (result == Mojo.RESULT_OK) {
+      controller.enqueue(new Uint8Array(chunk, 0, numBytes));
+      return;
+    } else if (result == Mojo.RESULT_FAILED_PRECONDITION) {
+      controller.close();
+      return;
+    } else if (result == Mojo.RESULT_SHOULD_WAIT) {
+      await this.readable();
+      return this.pull(controller);
+    }
+  }
+
+  cancel() {
+    if (this.watcher_)
+      this.watcher_.cancel();
+    this.consumer_.close();
+  }
+
+  readable() {
+    return new Promise((resolve) => {
+      this.watcher_ =
+          this.consumer_.watch({ readable: true, peerClosed: true }, () => {
+            this.watcher_.cancel();
+            this.watcher_ = undefined;
+            resolve();
+          });
+    });
+  }
+}
+
+// Implementation of an UnderlyingSink to create a WritableStream from a Mojo
+// data pipe producer handle.
+class DataPipeSink {
+  constructor(producer) {
+    this._producer = producer;
+  }
+
+  async write(chunk, controller) {
+    while (true) {
+      let {result, numBytes} = this._producer.writeData(chunk);
+      if (result == Mojo.RESULT_OK) {
+        if (numBytes == chunk.byteLength) {
+          return;
+        }
+        chunk = chunk.slice(numBytes);
+      } else if (result == Mojo.RESULT_FAILED_PRECONDITION) {
+        throw new DOMException('The pipe is closed.', 'InvalidStateError');
+      } else if (result == Mojo.RESULT_SHOULD_WAIT) {
+        await this.writable();
+      }
+    }
+  }
+
+  close() {
+    assert_equals(undefined, this._watcher);
+    this._producer.close();
+  }
+
+  abort(reason) {
+    if (this._watcher)
+      this._watcher.cancel();
+    this._producer.close();
+  }
+
+  writable() {
+    return new Promise((resolve) => {
+      this._watcher =
+          this._producer.watch({ writable: true, peerClosed: true }, () => {
+            this._watcher.cancel();
+            this._watcher = undefined;
+            resolve();
+          });
+    });
+  }
+}
+
+// Implementation of device.mojom.SerialPort.
+class FakeSerialPort {
+  constructor() {
+    this.inputSignals_ = {
+      dataCarrierDetect: false,
+      clearToSend: false,
+      ringIndicator: false,
+      dataSetReady: false
+    };
+    this.inputSignalFailure_ = false;
+    this.outputSignals_ = {
+      dataTerminalReady: false,
+      requestToSend: false,
+      break: false
+    };
+    this.outputSignalFailure_ = false;
+  }
+
+  open(options, client) {
+    if (this.receiver_ !== undefined) {
+      // Port already open.
+      return null;
+    }
+
+    let port = new SerialPortRemote();
+    this.receiver_ = new SerialPortReceiver(this);
+    this.receiver_.$.bindHandle(port.$.bindNewPipeAndPassReceiver().handle);
+
+    this.options_ = options;
+    this.client_ = client;
+    // OS typically sets DTR on open.
+    this.outputSignals_.dataTerminalReady = true;
+
+    return port;
+  }
+
+  write(data) {
+    return this.writer_.write(data);
+  }
+
+  read() {
+    return this.reader_.read();
+  }
+
+  // Reads from the port until at least |targetLength| is read or the stream is
+  // closed. The data is returned as a combined Uint8Array.
+  readWithLength(targetLength) {
+    return readWithLength(this.reader_, targetLength);
+  }
+
+  simulateReadError(error) {
+    this.writer_.close();
+    this.writer_.releaseLock();
+    this.writer_ = undefined;
+    this.writable_ = undefined;
+    this.client_.onReadError(error);
+  }
+
+  simulateParityError() {
+    this.simulateReadError(SerialReceiveError.PARITY_ERROR);
+  }
+
+  simulateDisconnectOnRead() {
+    this.simulateReadError(SerialReceiveError.DISCONNECTED);
+  }
+
+  simulateWriteError(error) {
+    this.reader_.cancel();
+    this.reader_ = undefined;
+    this.readable_ = undefined;
+    this.client_.onSendError(error);
+  }
+
+  simulateSystemErrorOnWrite() {
+    this.simulateWriteError(SerialSendError.SYSTEM_ERROR);
+  }
+
+  simulateDisconnectOnWrite() {
+    this.simulateWriteError(SerialSendError.DISCONNECTED);
+  }
+
+  simulateInputSignals(signals) {
+    this.inputSignals_ = signals;
+  }
+
+  simulateInputSignalFailure(fail) {
+    this.inputSignalFailure_ = fail;
+  }
+
+  get outputSignals() {
+    return this.outputSignals_;
+  }
+
+  simulateOutputSignalFailure(fail) {
+    this.outputSignalFailure_ = fail;
+  }
+
+  writable() {
+    if (this.writable_)
+      return Promise.resolve();
+
+    if (!this.writablePromise_) {
+      this.writablePromise_ = new Promise((resolve) => {
+        this.writableResolver_ = resolve;
+      });
+    }
+
+    return this.writablePromise_;
+  }
+
+  readable() {
+    if (this.readable_)
+      return Promise.resolve();
+
+    if (!this.readablePromise_) {
+      this.readablePromise_ = new Promise((resolve) => {
+        this.readableResolver_ = resolve;
+      });
+    }
+
+    return this.readablePromise_;
+  }
+
+  async startWriting(in_stream) {
+    this.readable_ = new ReadableStream(new DataPipeSource(in_stream));
+    this.reader_ = this.readable_.getReader();
+    if (this.readableResolver_) {
+      this.readableResolver_();
+      this.readableResolver_ = undefined;
+      this.readablePromise_ = undefined;
+    }
+  }
+
+  async startReading(out_stream) {
+    this.writable_ = new WritableStream(new DataPipeSink(out_stream));
+    this.writer_ = this.writable_.getWriter();
+    if (this.writableResolver_) {
+      this.writableResolver_();
+      this.writableResolver_ = undefined;
+      this.writablePromise_ = undefined;
+    }
+  }
+
+  async flush(mode) {
+    switch (mode) {
+      case SerialPortFlushMode.kReceive:
+        this.writer_.abort();
+        this.writer_.releaseLock();
+        this.writer_ = undefined;
+        this.writable_ = undefined;
+        break;
+      case SerialPortFlushMode.kTransmit:
+        this.reader_.cancel();
+        this.reader_ = undefined;
+        this.readable_ = undefined;
+        break;
+    }
+  }
+
+  async drain() {
+    await this.reader_.closed;
+  }
+
+  async getControlSignals() {
+    if (this.inputSignalFailure_) {
+      return {signals: null};
+    }
+
+    const signals = {
+      dcd: this.inputSignals_.dataCarrierDetect,
+      cts: this.inputSignals_.clearToSend,
+      ri: this.inputSignals_.ringIndicator,
+      dsr: this.inputSignals_.dataSetReady
+    };
+    return {signals};
+  }
+
+  async setControlSignals(signals) {
+    if (this.outputSignalFailure_) {
+      return {success: false};
+    }
+
+    if (signals.hasDtr) {
+      this.outputSignals_.dataTerminalReady = signals.dtr;
+    }
+    if (signals.hasRts) {
+      this.outputSignals_.requestToSend = signals.rts;
+    }
+    if (signals.hasBrk) {
+      this.outputSignals_.break = signals.brk;
+    }
+    return { success: true };
+  }
+
+  async configurePort(options) {
+    this.options_ = options;
+    return { success: true };
+  }
+
+  async getPortInfo() {
+    return {
+      bitrate: this.options_.bitrate,
+      dataBits: this.options_.datBits,
+      parityBit: this.options_.parityBit,
+      stopBits: this.options_.stopBits,
+      ctsFlowControl:
+          this.options_.hasCtsFlowControl && this.options_.ctsFlowControl,
+    };
+  }
+
+  async close() {
+    // OS typically clears DTR on close.
+    this.outputSignals_.dataTerminalReady = false;
+    if (this.writer_) {
+      this.writer_.close();
+      this.writer_.releaseLock();
+      this.writer_ = undefined;
+    }
+    this.writable_ = undefined;
+
+    // Close the receiver asynchronously so the reply to this message can be
+    // sent first.
+    const receiver = this.receiver_;
+    this.receiver_ = undefined;
+    setTimeout(() => {
+      receiver.$.close();
+    }, 0);
+
+    return {};
+  }
+}
+
+// Implementation of blink.mojom.SerialService.
+class FakeSerialService {
+  constructor() {
+    this.interceptor_ =
+        new MojoInterfaceInterceptor(SerialService.$interfaceName);
+    this.interceptor_.oninterfacerequest = e => this.bind(e.handle);
+    this.receiver_ = new SerialServiceReceiver(this);
+    this.clients_ = [];
+    this.nextToken_ = 0;
+    this.reset();
+  }
+
+  start() {
+    this.interceptor_.start();
+  }
+
+  stop() {
+    this.interceptor_.stop();
+  }
+
+  reset() {
+    this.ports_ = new Map();
+    this.selectedPort_ = null;
+  }
+
+  addPort(info) {
+    let portInfo = {};
+    if (info?.usbVendorId !== undefined) {
+      portInfo.hasUsbVendorId = true;
+      portInfo.usbVendorId = info.usbVendorId;
+    }
+    if (info?.usbProductId !== undefined) {
+      portInfo.hasUsbProductId = true;
+      portInfo.usbProductId = info.usbProductId;
+    }
+
+    let token = ++this.nextToken_;
+    portInfo.token = {high: 0n, low: BigInt(token)};
+
+    let record = {
+      portInfo: portInfo,
+      fakePort: new FakeSerialPort(),
+    };
+    this.ports_.set(token, record);
+
+    for (let client of this.clients_) {
+      client.onPortAdded(portInfo);
+    }
+
+    return token;
+  }
+
+  removePort(token) {
+    let record = this.ports_.get(token);
+    if (record === undefined) {
+      return;
+    }
+
+    this.ports_.delete(token);
+
+    for (let client of this.clients_) {
+      client.onPortRemoved(record.portInfo);
+    }
+  }
+
+  setSelectedPort(token) {
+    this.selectedPort_ = this.ports_.get(token);
+  }
+
+  getFakePort(token) {
+    let record = this.ports_.get(token);
+    if (record === undefined)
+      return undefined;
+    return record.fakePort;
+  }
+
+  bind(handle) {
+    this.receiver_.$.bindHandle(handle);
+  }
+
+  async setClient(client_remote) {
+    this.clients_.push(client_remote);
+  }
+
+  async getPorts() {
+    return {
+      ports: Array.from(this.ports_, ([token, record]) => record.portInfo)
+    };
+  }
+
+  async requestPort(filters) {
+    if (this.selectedPort_)
+      return { port: this.selectedPort_.portInfo };
+    else
+      return { port: null };
+  }
+
+  async openPort(token, options, client) {
+    let record = this.ports_.get(Number(token.low));
+    if (record !== undefined) {
+      return {port: record.fakePort.open(options, client)};
+    } else {
+      return {port: null};
+    }
+  }
+
+  async forgetPort(token) {
+    let record = this.ports_.get(Number(token.low));
+    if (record === undefined) {
+      return {success: false};
+    }
+
+    this.ports_.delete(Number(token.low));
+    if (record.fakePort.receiver_) {
+      record.fakePort.receiver_.$.close();
+      record.fakePort.receiver_ = undefined;
+    }
+    return {success: true};
+  }
+}
+
+export const fakeSerialService = new FakeSerialService();
diff --git a/testing/web-platform/tests/resources/chromium/generic_sensor_mocks.js b/testing/web-platform/tests/resources/chromium/generic_sensor_mocks.js
new file mode 100644
index 0000000000..98a29c2104
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/generic_sensor_mocks.js
@@ -0,0 +1,519 @@
+import {ReportingMode, Sensor, SensorClientRemote, SensorReceiver, SensorRemote, SensorType} from '/gen/services/device/public/mojom/sensor.mojom.m.js';
+import {SensorCreationResult, SensorInitParams_READ_BUFFER_SIZE_FOR_TESTS, SensorProvider, SensorProviderReceiver} from '/gen/services/device/public/mojom/sensor_provider.mojom.m.js';
+
+// A "sliding window" that iterates over |data| and returns one item at a
+// time, advancing and wrapping around as needed. |data| must be an array of
+// arrays.
+self.RingBuffer = class {
+  constructor(data) {
+    this.bufferPosition_ = 0;
+    // Validate |data|'s format and deep-copy every element.
+    this.data_ = Array.from(data, element => {
+      if (!Array.isArray(element)) {
+        throw new TypeError('Every |data| element must be an array.');
+      }
+      return Array.from(element);
+    })
+  }
+
+  next() {
+    const value = this.data_[this.bufferPosition_];
+    this.bufferPosition_ = (this.bufferPosition_ + 1) % this.data_.length;
+    return { done: false, value: value };
+  }
+
+  value() {
+    return this.data_[this.bufferPosition_];
+  }
+
+  [Symbol.iterator]() {
+    return this;
+  }
+};
+
+class DefaultSensorTraits {
+  // https://w3c.github.io/sensors/#threshold-check-algorithm
+  static isSignificantlyDifferent(reading1, reading2) {
+    return true;
+  }
+
+  // https://w3c.github.io/sensors/#reading-quantization-algorithm
+  static roundToMultiple(reading) {
+    return reading;
+  }
+
+  // https://w3c.github.io/ambient-light/#ambient-light-threshold-check-algorithm
+  static areReadingsEqual(reading1, reading2) {
+    return false;
+  }
+}
+
+class AmbientLightSensorTraits extends DefaultSensorTraits {
+  // https://w3c.github.io/ambient-light/#reduce-sensor-accuracy
+  static #ROUNDING_MULTIPLE = 50;
+  static #SIGNIFICANCE_THRESHOLD = 25;
+
+  // https://w3c.github.io/ambient-light/#ambient-light-threshold-check-algorithm
+  static isSignificantlyDifferent([illuminance1], [illuminance2]) {
+    return Math.abs(illuminance1 - illuminance2) >=
+        this.#SIGNIFICANCE_THRESHOLD;
+  }
+
+  // https://w3c.github.io/ambient-light/#ambient-light-reading-quantization-algorithm
+  static roundToMultiple(reading) {
+    const illuminance = reading[0];
+    const scaledValue =
+        illuminance / AmbientLightSensorTraits.#ROUNDING_MULTIPLE;
+    let roundedReading = reading.splice();
+
+    if (illuminance < 0.0) {
+      roundedReading[0] = -AmbientLightSensorTraits.#ROUNDING_MULTIPLE *
+          Math.floor(-scaledValue + 0.5);
+    } else {
+      roundedReading[0] = AmbientLightSensorTraits.#ROUNDING_MULTIPLE *
+          Math.floor(scaledValue + 0.5);
+    }
+
+    return roundedReading;
+  }
+
+  // https://w3c.github.io/ambient-light/#ambient-light-threshold-check-algorithm
+  static areReadingsEqual([illuminance1], [illuminance2]) {
+    return illuminance1 === illuminance2;
+  }
+}
+
+self.GenericSensorTest = (() => {
+  // Default sensor frequency in default configurations.
+  const DEFAULT_FREQUENCY = 5;
+
+  // Class that mocks Sensor interface defined in
+  // https://cs.chromium.org/chromium/src/services/device/public/mojom/sensor.mojom
+  class MockSensor {
+    static #BUFFER_OFFSET_TIMESTAMP = 1;
+    static #BUFFER_OFFSET_READINGS = 2;
+
+    constructor(sensorRequest, buffer, reportingMode, sensorType) {
+      this.client_ = null;
+      this.startShouldFail_ = false;
+      this.notifyOnReadingChange_ = true;
+      this.reportingMode_ = reportingMode;
+      this.sensorType_ = sensorType;
+      this.sensorReadingTimerId_ = null;
+      this.readingData_ = null;
+      this.requestedFrequencies_ = [];
+      // The Blink implementation (third_party/blink/renderer/modules/sensor/sensor.cc)
+      // sets a timestamp by creating a DOMHighResTimeStamp from a given platform timestamp.
+      // In this mock implementation we use a starting value
+      // and an increment step value that resemble a platform timestamp reasonably enough.
+      this.timestamp_ = window.performance.timeOrigin;
+      // |buffer| represents a SensorReadingSharedBuffer on the C++ side in
+      // Chromium. It consists, in this order, of a
+      // SensorReadingField<OneWriterSeqLock> (an 8-byte union that includes
+      // 32-bit integer used by the lock class), and a SensorReading consisting
+      // of an 8-byte timestamp and 4 8-byte reading fields.
+      //
+      // |this.buffer_[0]| is zeroed by default, which allows OneWriterSeqLock
+      // to work with our custom memory buffer that did not actually create a
+      // OneWriterSeqLock instance. It is never changed manually here.
+      //
+      // Use MockSensor.#BUFFER_OFFSET_TIMESTAMP and
+      // MockSensor.#BUFFER_OFFSET_READINGS to access the other positions in
+      // |this.buffer_| without having to hardcode magic numbers in the code.
+      this.buffer_ = buffer;
+      this.buffer_.fill(0);
+      this.receiver_ = new SensorReceiver(this);
+      this.receiver_.$.bindHandle(sensorRequest.handle);
+      this.lastRawReading_ = null;
+      this.lastRoundedReading_ = null;
+
+      if (sensorType == SensorType.AMBIENT_LIGHT) {
+        this.sensorTraits = AmbientLightSensorTraits;
+      } else {
+        this.sensorTraits = DefaultSensorTraits;
+      }
+    }
+
+    // Returns default configuration.
+    async getDefaultConfiguration() {
+      return { frequency: DEFAULT_FREQUENCY };
+    }
+
+    // Adds configuration for the sensor and starts reporting fake data
+    // through setSensorReading function.
+    async addConfiguration(configuration) {
+      this.requestedFrequencies_.push(configuration.frequency);
+      // Sort using descending order.
+      this.requestedFrequencies_.sort(
+          (first, second) => { return second - first });
+
+      if (!this.startShouldFail_ )
+        this.startReading();
+
+      return { success: !this.startShouldFail_ };
+    }
+
+    // Removes sensor configuration from the list of active configurations and
+    // stops notification about sensor reading changes if
+    // requestedFrequencies_ is empty.
+    removeConfiguration(configuration) {
+      const index = this.requestedFrequencies_.indexOf(configuration.frequency);
+      if (index == -1)
+        return;
+
+      this.requestedFrequencies_.splice(index, 1);
+      if (this.requestedFrequencies_.length === 0)
+        this.stopReading();
+    }
+
+    // ConfigureReadingChangeNotifications(bool enabled)
+    // Configures whether to report a reading change when in ON_CHANGE
+    // reporting mode.
+    configureReadingChangeNotifications(notifyOnReadingChange) {
+      this.notifyOnReadingChange_ = notifyOnReadingChange;
+    }
+
+    resume() {
+      this.startReading();
+    }
+
+    suspend() {
+      this.stopReading();
+    }
+
+    // Mock functions
+
+    // Resets mock Sensor state.
+    reset() {
+      this.stopReading();
+      this.startShouldFail_ = false;
+      this.requestedFrequencies_ = [];
+      this.notifyOnReadingChange_ = true;
+      this.readingData_ = null;
+      this.buffer_.fill(0);
+      this.receiver_.$.close();
+      this.lastRawReading_ = null;
+      this.lastRoundedReading_ = null;
+    }
+
+    // Sets fake data that is used to deliver sensor reading updates.
+    setSensorReading(readingData) {
+      this.readingData_ = new RingBuffer(readingData);
+    }
+
+    // This is a workaround to accommodate Blink's Device Orientation
+    // implementation. In general, all tests should use setSensorReading()
+    // instead.
+    setSensorReadingImmediately(readingData) {
+      this.setSensorReading(readingData);
+
+      const reading = this.readingData_.value();
+      this.buffer_.set(reading, MockSensor.#BUFFER_OFFSET_READINGS);
+      this.buffer_[MockSensor.#BUFFER_OFFSET_TIMESTAMP] = this.timestamp_++;
+    }
+
+    // Sets flag that forces sensor to fail when addConfiguration is invoked.
+    setStartShouldFail(shouldFail) {
+      this.startShouldFail_ = shouldFail;
+    }
+
+    startReading() {
+      if (this.readingData_ != null) {
+        this.stopReading();
+      }
+      let maxFrequencyUsed = this.requestedFrequencies_[0];
+      let timeout = (1 / maxFrequencyUsed) * 1000;
+      this.sensorReadingTimerId_ = window.setInterval(() => {
+        if (this.readingData_) {
+          // |buffer_| is a TypedArray, so we need to make sure pass an
+          // array to set().
+          const reading = this.readingData_.next().value;
+          if (!Array.isArray(reading)) {
+            throw new TypeError("startReading(): The readings passed to " +
+              "setSensorReading() must be arrays");
+          }
+
+          if (this.reportingMode_ == ReportingMode.ON_CHANGE &&
+              this.lastRawReading_ !== null &&
+              !this.sensorTraits.isSignificantlyDifferent(
+                  this.lastRawReading_, reading)) {
+            // In case new value is not significantly different compared to
+            // old value, new value is not sent.
+            return;
+          }
+
+          this.lastRawReading_ = reading.slice();
+          const roundedReading = this.sensorTraits.roundToMultiple(reading);
+
+          if (this.reportingMode_ == ReportingMode.ON_CHANGE &&
+              this.lastRoundedReading_ !== null &&
+              this.sensorTraits.areReadingsEqual(
+                roundedReading, this.lastRoundedReading_)) {
+            // In case new rounded value is not different compared to old
+            // value, new value is not sent.
+            return;
+          }
+          this.buffer_.set(roundedReading, MockSensor.#BUFFER_OFFSET_READINGS);
+          this.lastRoundedReading_ = roundedReading;
+        }
+
+        // For all tests sensor reading should have monotonically
+        // increasing timestamp.
+        this.buffer_[MockSensor.#BUFFER_OFFSET_TIMESTAMP] = this.timestamp_++;
+
+        if (this.reportingMode_ === ReportingMode.ON_CHANGE &&
+            this.notifyOnReadingChange_) {
+          this.client_.sensorReadingChanged();
+        }
+      }, timeout);
+    }
+
+    stopReading() {
+      if (this.sensorReadingTimerId_ != null) {
+        window.clearInterval(this.sensorReadingTimerId_);
+        this.sensorReadingTimerId_ = null;
+      }
+    }
+
+    getSamplingFrequency() {
+      if (this.requestedFrequencies_.length == 0) {
+        throw new Error("getSamplingFrequency(): No configured frequency");
+      }
+       return this.requestedFrequencies_[0];
+    }
+
+    isReadingData() {
+      return this.sensorReadingTimerId_ != null;
+    }
+  }
+
+  // Class that mocks SensorProvider interface defined in
+  // https://cs.chromium.org/chromium/src/services/device/public/mojom/sensor_provider.mojom
+  class MockSensorProvider {
+    constructor() {
+      this.readingSizeInBytes_ =
+          Number(SensorInitParams_READ_BUFFER_SIZE_FOR_TESTS);
+      this.sharedBufferSizeInBytes_ =
+          this.readingSizeInBytes_ * (SensorType.MAX_VALUE + 1);
+      let rv = Mojo.createSharedBuffer(this.sharedBufferSizeInBytes_);
+      if (rv.result != Mojo.RESULT_OK) {
+        throw new Error('MockSensorProvider: Failed to create shared buffer');
+      }
+      const handle = rv.handle;
+      rv = handle.mapBuffer(0, this.sharedBufferSizeInBytes_);
+      if (rv.result != Mojo.RESULT_OK) {
+        throw new Error("MockSensorProvider: Failed to map shared buffer");
+      }
+      this.shmemArrayBuffer_ = rv.buffer;
+      rv = handle.duplicateBufferHandle({readOnly: true});
+      if (rv.result != Mojo.RESULT_OK) {
+        throw new Error(
+            'MockSensorProvider: failed to duplicate shared buffer');
+      }
+      this.readOnlySharedBufferHandle_ = rv.handle;
+      this.activeSensors_ = new Map();
+      this.resolveFuncs_ = new Map();
+      this.getSensorShouldFail_ = new Map();
+      this.permissionsDenied_ = new Map();
+      this.maxFrequency_ = 60;
+      this.minFrequency_ = 1;
+      this.mojomSensorType_ = new Map([
+        ['Accelerometer', SensorType.ACCELEROMETER],
+        ['LinearAccelerationSensor', SensorType.LINEAR_ACCELERATION],
+        ['GravitySensor', SensorType.GRAVITY],
+        ['AmbientLightSensor', SensorType.AMBIENT_LIGHT],
+        ['Gyroscope', SensorType.GYROSCOPE],
+        ['Magnetometer', SensorType.MAGNETOMETER],
+        ['AbsoluteOrientationSensor',
+            SensorType.ABSOLUTE_ORIENTATION_QUATERNION],
+        ['AbsoluteOrientationEulerAngles',
+            SensorType.ABSOLUTE_ORIENTATION_EULER_ANGLES],
+        ['RelativeOrientationSensor',
+            SensorType.RELATIVE_ORIENTATION_QUATERNION],
+        ['RelativeOrientationEulerAngles',
+            SensorType.RELATIVE_ORIENTATION_EULER_ANGLES],
+        ['ProximitySensor', SensorType.PROXIMITY]
+      ]);
+      this.receiver_ = new SensorProviderReceiver(this);
+
+      this.interceptor_ =
+          new MojoInterfaceInterceptor(SensorProvider.$interfaceName);
+      this.interceptor_.oninterfacerequest = e => {
+        this.bindToPipe(e.handle);
+      };
+      this.interceptor_.start();
+    }
+
+    // Returns initialized Sensor proxy to the client.
+    async getSensor(type) {
+      if (this.getSensorShouldFail_.get(type)) {
+        return {result: SensorCreationResult.ERROR_NOT_AVAILABLE,
+                initParams: null};
+      }
+      if (this.permissionsDenied_.get(type)) {
+        return {result: SensorCreationResult.ERROR_NOT_ALLOWED,
+                initParams: null};
+      }
+
+      const offset = type * this.readingSizeInBytes_;
+      const reportingMode = ReportingMode.ON_CHANGE;
+
+      const sensor = new SensorRemote();
+      if (!this.activeSensors_.has(type)) {
+        const shmemView = new Float64Array(
+            this.shmemArrayBuffer_, offset,
+            this.readingSizeInBytes_ / Float64Array.BYTES_PER_ELEMENT);
+        const mockSensor = new MockSensor(
+            sensor.$.bindNewPipeAndPassReceiver(), shmemView, reportingMode,
+            type);
+        this.activeSensors_.set(type, mockSensor);
+        this.activeSensors_.get(type).client_ = new SensorClientRemote();
+      }
+
+      const rv = this.readOnlySharedBufferHandle_.duplicateBufferHandle(
+          {readOnly: true});
+      if (rv.result != Mojo.RESULT_OK) {
+        throw new Error('getSensor(): failed to duplicate shared buffer');
+      }
+
+      const defaultConfig = { frequency: DEFAULT_FREQUENCY };
+      // Consider sensor traits to meet assertions in C++ code (see
+      // services/device/public/cpp/generic_sensor/sensor_traits.h)
+      if (type == SensorType.AMBIENT_LIGHT || type == SensorType.MAGNETOMETER) {
+        this.maxFrequency_ = Math.min(10, this.maxFrequency_);
+      }
+
+      const client = this.activeSensors_.get(type).client_;
+      const initParams = {
+        sensor,
+        clientReceiver: client.$.bindNewPipeAndPassReceiver(),
+        memory: {buffer: rv.handle},
+        bufferOffset: BigInt(offset),
+        mode: reportingMode,
+        defaultConfiguration: defaultConfig,
+        minimumFrequency: this.minFrequency_,
+        maximumFrequency: this.maxFrequency_
+      };
+
+      if (this.resolveFuncs_.has(type)) {
+        for (let resolveFunc of this.resolveFuncs_.get(type)) {
+          resolveFunc(this.activeSensors_.get(type));
+        }
+        this.resolveFuncs_.delete(type);
+      }
+
+      return {result: SensorCreationResult.SUCCESS, initParams};
+    }
+
+    // Binds object to mojo message pipe
+    bindToPipe(pipe) {
+      this.receiver_.$.bindHandle(pipe);
+    }
+
+    // Mock functions
+
+    // Resets state of mock SensorProvider between test runs.
+    reset() {
+      for (const sensor of this.activeSensors_.values()) {
+        sensor.reset();
+      }
+      this.activeSensors_.clear();
+      this.resolveFuncs_.clear();
+      this.getSensorShouldFail_.clear();
+      this.permissionsDenied_.clear();
+      this.maxFrequency_ = 60;
+      this.minFrequency_ = 1;
+      this.receiver_.$.close();
+      this.interceptor_.stop();
+    }
+
+    // Sets flag that forces mock SensorProvider to fail when getSensor() is
+    // invoked.
+    setGetSensorShouldFail(sensorType, shouldFail) {
+      this.getSensorShouldFail_.set(this.mojomSensorType_.get(sensorType),
+          shouldFail);
+    }
+
+    setPermissionsDenied(sensorType, permissionsDenied) {
+      this.permissionsDenied_.set(this.mojomSensorType_.get(sensorType),
+          permissionsDenied);
+    }
+
+    // Returns mock sensor that was created in getSensor to the layout test.
+    getCreatedSensor(sensorType) {
+      const type = this.mojomSensorType_.get(sensorType);
+      if (typeof type != "number") {
+        throw new TypeError(`getCreatedSensor(): Invalid sensor type ${sensorType}`);
+      }
+
+      if (this.activeSensors_.has(type)) {
+        return Promise.resolve(this.activeSensors_.get(type));
+      }
+
+      return new Promise(resolve => {
+        if (!this.resolveFuncs_.has(type)) {
+          this.resolveFuncs_.set(type, []);
+        }
+        this.resolveFuncs_.get(type).push(resolve);
+      });
+    }
+
+    // Sets the maximum frequency for a concrete sensor.
+    setMaximumSupportedFrequency(frequency) {
+      this.maxFrequency_ = frequency;
+    }
+
+    // Sets the minimum frequency for a concrete sensor.
+    setMinimumSupportedFrequency(frequency) {
+      this.minFrequency_ = frequency;
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    sensorProvider: null
+  }
+
+  class GenericSensorTestChromium {
+    constructor() {
+      Object.freeze(this); // Make it immutable.
+    }
+
+    async initialize() {
+      if (testInternal.initialized)
+        throw new Error('Call reset() before initialize().');
+
+      // Grant sensor permissions for Chromium testdriver.
+      // testdriver.js only works in the top-level browsing context, so do
+      // nothing if we're in e.g. an iframe.
+      if (window.parent === window) {
+        for (const entry
+                 of ['accelerometer', 'gyroscope', 'magnetometer',
+                     'ambient-light-sensor']) {
+          await test_driver.set_permission({name: entry}, 'granted');
+        }
+      }
+
+      testInternal.sensorProvider = new MockSensorProvider;
+      testInternal.initialized = true;
+    }
+    // Resets state of sensor mocks between test runs.
+    async reset() {
+      if (!testInternal.initialized)
+        throw new Error('Call initialize() before reset().');
+      testInternal.sensorProvider.reset();
+      testInternal.sensorProvider = null;
+      testInternal.initialized = false;
+
+      // Wait for an event loop iteration to let any pending mojo commands in
+      // the sensor provider finish.
+      await new Promise(resolve => setTimeout(resolve, 0));
+    }
+
+    getSensorProvider() {
+      return testInternal.sensorProvider;
+    }
+  }
+
+  return GenericSensorTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/generic_sensor_mocks.js.headers b/testing/web-platform/tests/resources/chromium/generic_sensor_mocks.js.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/generic_sensor_mocks.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
diff --git a/testing/web-platform/tests/resources/chromium/mock-barcodedetection.js b/testing/web-platform/tests/resources/chromium/mock-barcodedetection.js
new file mode 100644
index 0000000000..b0d2e0af0a
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-barcodedetection.js
@@ -0,0 +1,136 @@
+import {BarcodeDetectionReceiver, BarcodeFormat} from '/gen/services/shape_detection/public/mojom/barcodedetection.mojom.m.js';
+import {BarcodeDetectionProvider, BarcodeDetectionProviderReceiver} from '/gen/services/shape_detection/public/mojom/barcodedetection_provider.mojom.m.js';
+
+self.BarcodeDetectionTest = (() => {
+  // Class that mocks BarcodeDetectionProvider interface defined in
+  // https://cs.chromium.org/chromium/src/services/shape_detection/public/mojom/barcodedetection_provider.mojom
+  class MockBarcodeDetectionProvider {
+    constructor() {
+      this.receiver_ = new BarcodeDetectionProviderReceiver(this);
+
+      this.interceptor_ = new MojoInterfaceInterceptor(
+          BarcodeDetectionProvider.$interfaceName);
+      this.interceptor_.oninterfacerequest = e => {
+        if (this.should_close_pipe_on_request_)
+          e.handle.close();
+        else
+          this.receiver_.$.bindHandle(e.handle);
+      }
+      this.interceptor_.start();
+      this.should_close_pipe_on_request_ = false;
+    }
+
+    createBarcodeDetection(request, options) {
+      this.mockService_ = new MockBarcodeDetection(request, options);
+    }
+
+    enumerateSupportedFormats() {
+      return {
+        supportedFormats: [
+          BarcodeFormat.AZTEC,
+          BarcodeFormat.DATA_MATRIX,
+          BarcodeFormat.QR_CODE,
+        ]
+      };
+    }
+
+    getFrameData() {
+      return this.mockService_.bufferData_;
+    }
+
+    getFormats() {
+     return this.mockService_.options_.formats;
+    }
+
+    reset() {
+      this.mockService_ = null;
+      this.should_close_pipe_on_request_ = false;
+      this.receiver_.$.close();
+      this.interceptor_.stop();
+    }
+
+    // simulate a 'no implementation available' case
+    simulateNoImplementation() {
+      this.should_close_pipe_on_request_ = true;
+    }
+  }
+
+  // Class that mocks BarcodeDetection interface defined in
+  // https://cs.chromium.org/chromium/src/services/shape_detection/public/mojom/barcodedetection.mojom
+  class MockBarcodeDetection {
+    constructor(request, options) {
+      this.options_ = options;
+      this.receiver_ = new BarcodeDetectionReceiver(this);
+      this.receiver_.$.bindHandle(request.handle);
+    }
+
+    detect(bitmapData) {
+      this.bufferData_ =
+          new Uint32Array(getArrayBufferFromBigBuffer(bitmapData.pixelData));
+      return {
+        results: [
+          {
+            rawValue : "cats",
+            boundingBox: { x: 1.0, y: 1.0, width: 100.0, height: 100.0 },
+            format: BarcodeFormat.QR_CODE,
+            cornerPoints: [
+              { x: 1.0, y: 1.0 },
+              { x: 101.0, y: 1.0 },
+              { x: 101.0, y: 101.0 },
+              { x: 1.0, y: 101.0 }
+            ],
+          },
+          {
+            rawValue : "dogs",
+            boundingBox: { x: 2.0, y: 2.0, width: 50.0, height: 50.0 },
+            format: BarcodeFormat.CODE_128,
+            cornerPoints: [
+              { x: 2.0, y: 2.0 },
+              { x: 52.0, y: 2.0 },
+              { x: 52.0, y: 52.0 },
+              { x: 2.0, y: 52.0 }
+            ],
+          },
+        ],
+      };
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    MockBarcodeDetectionProvider: null
+  }
+
+  class BarcodeDetectionTestChromium {
+    constructor() {
+      Object.freeze(this); // Make it immutable.
+    }
+
+    initialize() {
+      if (testInternal.initialized)
+        throw new Error('Call reset() before initialize().');
+
+      testInternal.MockBarcodeDetectionProvider = new MockBarcodeDetectionProvider;
+      testInternal.initialized = true;
+    }
+
+    // Resets state of barcode detection mocks between test runs.
+    async reset() {
+      if (!testInternal.initialized)
+        throw new Error('Call initialize() before reset().');
+      testInternal.MockBarcodeDetectionProvider.reset();
+      testInternal.MockBarcodeDetectionProvider = null;
+      testInternal.initialized = false;
+
+      await new Promise(resolve => setTimeout(resolve, 0));
+    }
+
+    MockBarcodeDetectionProvider() {
+      return testInternal.MockBarcodeDetectionProvider;
+    }
+  }
+
+  return BarcodeDetectionTestChromium;
+})();
+
+self.BarcodeFormat = BarcodeFormat;
diff --git a/testing/web-platform/tests/resources/chromium/mock-barcodedetection.js.headers b/testing/web-platform/tests/resources/chromium/mock-barcodedetection.js.headers
new file mode 100644
index 0000000000..6c61a34a4e
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-barcodedetection.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
\ No newline at end of file
diff --git a/testing/web-platform/tests/resources/chromium/mock-battery-monitor.headers b/testing/web-platform/tests/resources/chromium/mock-battery-monitor.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-battery-monitor.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
diff --git a/testing/web-platform/tests/resources/chromium/mock-battery-monitor.js b/testing/web-platform/tests/resources/chromium/mock-battery-monitor.js
new file mode 100644
index 0000000000..8fa27bc56a
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-battery-monitor.js
@@ -0,0 +1,61 @@
+import {BatteryMonitor, BatteryMonitorReceiver} from '/gen/services/device/public/mojom/battery_monitor.mojom.m.js';
+
+class MockBatteryMonitor {
+  constructor() {
+    this.receiver_ = new BatteryMonitorReceiver(this);
+    this.interceptor_ =
+        new MojoInterfaceInterceptor(BatteryMonitor.$interfaceName);
+    this.interceptor_.oninterfacerequest = e =>
+        this.receiver_.$.bindHandle(e.handle);
+    this.reset();
+  }
+
+  start() {
+    this.interceptor_.start();
+  }
+
+  stop() {
+    this.interceptor_.stop();
+  }
+
+  reset() {
+    this.pendingRequests_ = [];
+    this.status_ = null;
+    this.lastKnownStatus_ = null;
+  }
+
+  queryNextStatus() {
+    const result = new Promise(resolve => this.pendingRequests_.push(resolve));
+    this.runCallbacks_();
+    return result;
+  }
+
+  setBatteryStatus(charging, chargingTime, dischargingTime, level) {
+    this.status_ = {charging, chargingTime, dischargingTime, level};
+    this.lastKnownStatus_ = this.status_;
+    this.runCallbacks_();
+  }
+
+  verifyBatteryStatus(manager) {
+    assert_not_equals(manager, undefined);
+    assert_not_equals(this.lastKnownStatus_, null);
+    assert_equals(manager.charging, this.lastKnownStatus_.charging);
+    assert_equals(manager.chargingTime, this.lastKnownStatus_.chargingTime);
+    assert_equals(
+        manager.dischargingTime, this.lastKnownStatus_.dischargingTime);
+    assert_equals(manager.level, this.lastKnownStatus_.level);
+  }
+
+  runCallbacks_() {
+    if (!this.status_ || !this.pendingRequests_.length)
+      return;
+
+    let result = {status: this.status_};
+    while (this.pendingRequests_.length) {
+      this.pendingRequests_.pop()(result);
+    }
+    this.status_ = null;
+  }
+}
+
+export const mockBatteryMonitor = new MockBatteryMonitor();
diff --git a/testing/web-platform/tests/resources/chromium/mock-direct-sockets.js b/testing/web-platform/tests/resources/chromium/mock-direct-sockets.js
new file mode 100644
index 0000000000..6d557f7a01
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-direct-sockets.js
@@ -0,0 +1,94 @@
+'use strict';
+
+import {DirectSocketsService, DirectSocketsServiceReceiver} from '/gen/third_party/blink/public/mojom/direct_sockets/direct_sockets.mojom.m.js';
+
+self.DirectSocketsServiceTest = (() => {
+  // Class that mocks DirectSocketsService interface defined in
+  // https://source.chromium.org/chromium/chromium/src/third_party/blink/public/mojom/direct_sockets/direct_sockets.mojom
+  class MockDirectSocketsService {
+    constructor() {
+      this.interceptor_ = new MojoInterfaceInterceptor(DirectSocketsService.$interfaceName);
+      this.receiver_ = new DirectSocketsServiceReceiver(this);
+      this.interceptor_.oninterfacerequest = e =>
+          this.receiver_.$.bindHandle(e.handle);
+      this.interceptor_.start();
+    }
+
+    reset() {
+      this.receiver_.$.close();
+      this.interceptor_.stop();
+    }
+
+    openTCPSocket(
+      options,
+      receiver,
+      observer) {
+      return Promise.resolve({
+        // return result = net:Error::NOT_IMPLEMENTED (code -11)
+        result: -11
+      });
+    }
+
+    openConnectedUDPSocket(
+      options,
+      receiver,
+      listener) {
+      return Promise.resolve({
+        // return result = net:Error::NOT_IMPLEMENTED (code -11)
+        result: -11
+      });
+    }
+
+    openBoundUDPSocket(
+      options,
+      receiver,
+      listener) {
+      return Promise.resolve({
+        // return result = net:Error::NOT_IMPLEMENTED (code -11)
+        result: -11
+      });
+    }
+
+    openTCPServerSocket(
+      options,
+      receiver) {
+      return Promise.resolve({
+        // return result = net:Error::NOT_IMPLEMENTED (code -11)
+        result: -11
+      });
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    mockDirectSocketsService: null
+  }
+
+  class DirectSocketsServiceTestChromium {
+    constructor() {
+      Object.freeze(this);  // Make it immutable.
+    }
+
+    initialize() {
+      if (!testInternal.initialized) {
+        testInternal = {
+          mockDirectSocketsService: new MockDirectSocketsService(),
+          initialized: true
+        };
+      }
+    }
+
+    async reset() {
+      if (testInternal.initialized) {
+        testInternal.mockDirectSocketsService.reset();
+        testInternal = {
+          mockDirectSocketsService: null,
+          initialized: false
+        };
+        await new Promise(resolve => setTimeout(resolve, 0));
+      }
+    }
+  }
+
+  return DirectSocketsServiceTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/mock-facedetection.js b/testing/web-platform/tests/resources/chromium/mock-facedetection.js
new file mode 100644
index 0000000000..7ae658621e
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-facedetection.js
@@ -0,0 +1,130 @@
+import {FaceDetectionReceiver, LandmarkType} from '/gen/services/shape_detection/public/mojom/facedetection.mojom.m.js';
+import {FaceDetectionProvider, FaceDetectionProviderReceiver} from '/gen/services/shape_detection/public/mojom/facedetection_provider.mojom.m.js';
+
+self.FaceDetectionTest = (() => {
+  // Class that mocks FaceDetectionProvider interface defined in
+  // https://cs.chromium.org/chromium/src/services/shape_detection/public/mojom/facedetection_provider.mojom
+  class MockFaceDetectionProvider {
+    constructor() {
+      this.receiver_ = new FaceDetectionProviderReceiver(this);
+
+      this.interceptor_ = new MojoInterfaceInterceptor(
+          FaceDetectionProvider.$interfaceName);
+      this.interceptor_.oninterfacerequest =
+         e => this.receiver_.$.bindHandle(e.handle);
+      this.interceptor_.start();
+    }
+
+    createFaceDetection(request, options) {
+      this.mockService_ = new MockFaceDetection(request, options);
+    }
+
+    getFrameData() {
+      return this.mockService_.bufferData_;
+    }
+
+    getMaxDetectedFaces() {
+     return this.mockService_.maxDetectedFaces_;
+    }
+
+    getFastMode () {
+      return this.mockService_.fastMode_;
+    }
+
+    reset() {
+      this.mockService_ = null;
+      this.receiver_.$.close();
+      this.interceptor_.stop();
+    }
+  }
+
+  // Class that mocks FaceDetection interface defined in
+  // https://cs.chromium.org/chromium/src/services/shape_detection/public/mojom/facedetection.mojom
+  class MockFaceDetection {
+    constructor(request, options) {
+      this.maxDetectedFaces_ = options.maxDetectedFaces;
+      this.fastMode_ = options.fastMode;
+      this.receiver_ = new FaceDetectionReceiver(this);
+      this.receiver_.$.bindHandle(request.handle);
+    }
+
+    detect(bitmapData) {
+      this.bufferData_ =
+          new Uint32Array(getArrayBufferFromBigBuffer(bitmapData.pixelData));
+      return Promise.resolve({
+        results: [
+          {
+            boundingBox: {x: 1.0, y: 1.0, width: 100.0, height: 100.0},
+            landmarks: [{
+              type: LandmarkType.EYE,
+              locations: [{x: 4.0, y: 5.0}]
+            },
+            {
+              type: LandmarkType.EYE,
+              locations: [
+                {x: 4.0, y: 5.0}, {x: 5.0, y: 4.0}, {x: 6.0, y: 3.0},
+                {x: 7.0, y: 4.0}, {x: 8.0, y: 5.0}, {x: 7.0, y: 6.0},
+                {x: 6.0, y: 7.0}, {x: 5.0, y: 6.0}
+              ]
+            }]
+          },
+          {
+            boundingBox: {x: 2.0, y: 2.0, width: 200.0, height: 200.0},
+            landmarks: [{
+              type: LandmarkType.NOSE,
+              locations: [{x: 100.0, y: 50.0}]
+            },
+            {
+              type: LandmarkType.NOSE,
+              locations: [
+                {x: 80.0, y: 50.0}, {x: 70.0, y: 60.0}, {x: 60.0, y: 70.0},
+                {x: 70.0, y: 60.0}, {x: 80.0, y: 70.0}, {x: 90.0, y: 80.0},
+                {x: 100.0, y: 70.0}, {x: 90.0, y: 60.0}, {x: 80.0, y: 50.0}
+              ]
+            }]
+          },
+          {
+            boundingBox: {x: 3.0, y: 3.0, width: 300.0, height: 300.0},
+            landmarks: []
+          },
+        ]
+      });
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    MockFaceDetectionProvider: null
+  }
+
+  class FaceDetectionTestChromium {
+    constructor() {
+      Object.freeze(this); // Make it immutable.
+    }
+
+    initialize() {
+      if (testInternal.initialized)
+        throw new Error('Call reset() before initialize().');
+
+      testInternal.MockFaceDetectionProvider = new MockFaceDetectionProvider;
+      testInternal.initialized = true;
+    }
+
+    // Resets state of face detection mocks between test runs.
+    async reset() {
+      if (!testInternal.initialized)
+        throw new Error('Call initialize() before reset().');
+      testInternal.MockFaceDetectionProvider.reset();
+      testInternal.MockFaceDetectionProvider = null;
+      testInternal.initialized = false;
+
+      await new Promise(resolve => setTimeout(resolve, 0));
+    }
+
+    MockFaceDetectionProvider() {
+      return testInternal.MockFaceDetectionProvider;
+    }
+  }
+
+  return FaceDetectionTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/mock-facedetection.js.headers b/testing/web-platform/tests/resources/chromium/mock-facedetection.js.headers
new file mode 100644
index 0000000000..6c61a34a4e
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-facedetection.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
\ No newline at end of file
diff --git a/testing/web-platform/tests/resources/chromium/mock-idle-detection.js b/testing/web-platform/tests/resources/chromium/mock-idle-detection.js
new file mode 100644
index 0000000000..54fe5dd01e
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-idle-detection.js
@@ -0,0 +1,80 @@
+import {IdleManager, IdleManagerError, IdleManagerReceiver} from '/gen/third_party/blink/public/mojom/idle/idle_manager.mojom.m.js';
+
+/**
+ * This is a testing framework that enables us to test the user idle detection
+ * by intercepting the connection between the renderer and the browser and
+ * exposing a mocking API for tests.
+ *
+ * Usage:
+ *
+ * 1) Include <script src="mock.js"></script> in your file.
+ * 2) Set expectations
+ *   expect(addMonitor).andReturn((threshold, monitorPtr, callback) => {
+ *     // mock behavior
+ *   })
+ * 3) Call navigator.idle.query()
+ *
+ * The mocking API is blink agnostic and is designed such that other engines
+ * could implement it too. Here are the symbols that are exposed to tests:
+ *
+ * - function addMonitor(): the main/only function that can be mocked.
+ * - function expect(): the main/only function that enables us to mock it.
+ * - function close(): disconnects the interceptor.
+ * - enum UserIdleState {IDLE, ACTIVE}: blink agnostic constants.
+ * - enum ScreenIdleState {LOCKED, UNLOCKED}: blink agnostic constants.
+ */
+
+class FakeIdleMonitor {
+  addMonitor(threshold, monitorPtr, callback) {
+    return this.handler.addMonitor(threshold, monitorPtr);
+  }
+  setHandler(handler) {
+    this.handler = handler;
+    return this;
+  }
+  setBinding(binding) {
+    this.binding = binding;
+    return this;
+  }
+  close() {
+    this.binding.$.close();
+  }
+}
+
+self.IdleDetectorError = {};
+
+self.addMonitor = function addMonitor(threshold, monitorPtr, callback) {
+  throw new Error("expected to be overriden by tests");
+}
+
+async function close() {
+  interceptor.close();
+}
+
+self.expect = function(call) {
+  return {
+    andReturn(callback) {
+      let handler = {};
+      handler[call.name] = callback;
+      interceptor.setHandler(handler);
+    }
+  };
+};
+
+function intercept() {
+  let result = new FakeIdleMonitor();
+
+  let binding = new IdleManagerReceiver(result);
+  let interceptor = new MojoInterfaceInterceptor(IdleManager.$interfaceName);
+  interceptor.oninterfacerequest = e => binding.$.bindHandle(e.handle);
+  interceptor.start();
+
+  self.IdleDetectorError.SUCCESS = IdleManagerError.kSuccess;
+  self.IdleDetectorError.PERMISSION_DISABLED =
+      IdleManagerError.kPermissionDisabled;
+
+  result.setBinding(binding);
+  return result;
+}
+
+const interceptor = intercept();
diff --git a/testing/web-platform/tests/resources/chromium/mock-imagecapture.js b/testing/web-platform/tests/resources/chromium/mock-imagecapture.js
new file mode 100644
index 0000000000..8424e1e36c
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-imagecapture.js
@@ -0,0 +1,309 @@
+import {BackgroundBlurMode, FillLightMode, ImageCapture, ImageCaptureReceiver, MeteringMode, RedEyeReduction} from '/gen/media/capture/mojom/image_capture.mojom.m.js';
+
+self.ImageCaptureTest = (() => {
+  // Class that mocks ImageCapture interface defined in
+  // https://cs.chromium.org/chromium/src/media/capture/mojom/image_capture.mojom
+  class MockImageCapture {
+    constructor() {
+      this.interceptor_ =
+          new MojoInterfaceInterceptor(ImageCapture.$interfaceName);
+      this.interceptor_.oninterfacerequest =
+        e => this.receiver_.$.bindHandle(e.handle);
+      this.interceptor_.start();
+
+      this.state_ = {
+        state: {
+          supportedWhiteBalanceModes: [
+            MeteringMode.SINGLE_SHOT,
+            MeteringMode.CONTINUOUS
+          ],
+          currentWhiteBalanceMode: MeteringMode.CONTINUOUS,
+          supportedExposureModes: [
+            MeteringMode.MANUAL,
+            MeteringMode.SINGLE_SHOT,
+            MeteringMode.CONTINUOUS
+          ],
+          currentExposureMode: MeteringMode.MANUAL,
+          supportedFocusModes: [
+            MeteringMode.MANUAL,
+            MeteringMode.SINGLE_SHOT
+          ],
+          currentFocusMode: MeteringMode.MANUAL,
+          pointsOfInterest: [{
+            x: 0.4,
+            y: 0.6
+          }],
+
+          exposureCompensation: {
+            min: -200.0,
+            max: 200.0,
+            current: 33.0,
+            step: 33.0
+          },
+          exposureTime: {
+            min: 100.0,
+            max: 100000.0,
+            current: 1000.0,
+            step: 100.0
+          },
+          colorTemperature: {
+            min: 2500.0,
+            max: 6500.0,
+            current: 6000.0,
+            step: 1000.0
+          },
+          iso: {
+            min: 100.0,
+            max: 12000.0,
+            current: 400.0,
+            step: 1.0
+          },
+
+          brightness: {
+            min: 1.0,
+            max: 10.0,
+            current: 5.0,
+            step: 1.0
+          },
+          contrast: {
+            min: 2.0,
+            max: 9.0,
+            current: 5.0,
+            step: 1.0
+          },
+          saturation: {
+            min: 3.0,
+            max: 8.0,
+            current: 6.0,
+            step: 1.0
+          },
+          sharpness: {
+            min: 4.0,
+            max: 7.0,
+            current: 7.0,
+            step: 1.0
+          },
+
+          focusDistance: {
+            min: 1.0,
+            max: 10.0,
+            current: 3.0,
+            step: 1.0
+          },
+
+          pan: {
+            min: 0.0,
+            max: 10.0,
+            current: 5.0,
+            step: 2.0
+          },
+
+          tilt: {
+            min: 0.0,
+            max: 10.0,
+            current: 5.0,
+            step: 2.0
+          },
+
+          zoom: {
+            min: 0.0,
+            max: 10.0,
+            current: 5.0,
+            step: 5.0
+          },
+
+          supportsTorch: true,
+          torch: false,
+
+          redEyeReduction: RedEyeReduction.CONTROLLABLE,
+          height: {
+            min: 240.0,
+            max: 2448.0,
+            current: 240.0,
+            step: 2.0
+          },
+          width: {
+            min: 320.0,
+            max: 3264.0,
+            current: 320.0,
+            step: 3.0
+          },
+          fillLightMode: [FillLightMode.AUTO, FillLightMode.FLASH],
+
+          supportedBackgroundBlurModes: [
+              BackgroundBlurMode.OFF,
+              BackgroundBlurMode.BLUR
+          ],
+          backgroundBlurMode: BackgroundBlurMode.OFF,
+        }
+      };
+      this.panTiltZoomPermissionStatus_ = null;
+      this.settings_ = null;
+      this.receiver_ = new ImageCaptureReceiver(this);
+    }
+
+    reset() {
+      this.receiver_.$.close();
+      this.interceptor_.stop();
+    }
+
+    async getPhotoState(source_id) {
+      const shouldKeepPanTiltZoom = await this.isPanTiltZoomPermissionGranted();
+      if (shouldKeepPanTiltZoom)
+        return Promise.resolve(this.state_);
+
+      const newState = {...this.state_};
+      newState.state.pan = {};
+      newState.state.tilt = {};
+      newState.state.zoom = {};
+      return Promise.resolve(newState);
+    }
+
+    async setPhotoOptions(source_id, settings) {
+      const isAllowedToControlPanTiltZoom = await this.isPanTiltZoomPermissionGranted();
+      if (!isAllowedToControlPanTiltZoom &&
+          (settings.hasPan || settings.hasTilt || settings.hasZoom)) {
+        return Promise.resolve({ success: false });
+      }
+      this.settings_ = settings;
+      if (settings.hasIso)
+        this.state_.state.iso.current = settings.iso;
+      if (settings.hasHeight)
+        this.state_.state.height.current = settings.height;
+      if (settings.hasWidth)
+        this.state_.state.width.current = settings.width;
+      if (settings.hasPan)
+        this.state_.state.pan.current = settings.pan;
+      if (settings.hasTilt)
+        this.state_.state.tilt.current = settings.tilt;
+      if (settings.hasZoom)
+        this.state_.state.zoom.current = settings.zoom;
+      if (settings.hasFocusMode)
+        this.state_.state.currentFocusMode = settings.focusMode;
+      if (settings.hasFocusDistance)
+        this.state_.state.focusDistance.current = settings.focusDistance;
+
+      if (settings.pointsOfInterest.length > 0) {
+        this.state_.state.pointsOfInterest =
+          settings.pointsOfInterest;
+      }
+
+      if (settings.hasExposureMode)
+        this.state_.state.currentExposureMode = settings.exposureMode;
+
+      if (settings.hasExposureCompensation) {
+        this.state_.state.exposureCompensation.current =
+          settings.exposureCompensation;
+      }
+      if (settings.hasExposureTime) {
+        this.state_.state.exposureTime.current =
+          settings.exposureTime;
+      }
+      if (settings.hasWhiteBalanceMode) {
+        this.state_.state.currentWhiteBalanceMode =
+          settings.whiteBalanceMode;
+      }
+      if (settings.hasFillLightMode)
+        this.state_.state.fillLightMode = [settings.fillLightMode];
+      if (settings.hasRedEyeReduction)
+        this.state_.state.redEyeReduction = settings.redEyeReduction;
+      if (settings.hasColorTemperature) {
+        this.state_.state.colorTemperature.current =
+          settings.colorTemperature;
+      }
+      if (settings.hasBrightness)
+        this.state_.state.brightness.current = settings.brightness;
+      if (settings.hasContrast)
+        this.state_.state.contrast.current = settings.contrast;
+      if (settings.hasSaturation)
+        this.state_.state.saturation.current = settings.saturation;
+      if (settings.hasSharpness)
+        this.state_.state.sharpness.current = settings.sharpness;
+
+      if (settings.hasTorch)
+        this.state_.state.torch = settings.torch;
+
+      if (settings.hasBackgroundBlurMode)
+        this.state_.state.backgroundBlurMode = [settings.backgroundBlurMode];
+
+      return Promise.resolve({
+        success: true
+      });
+    }
+
+    takePhoto(source_id) {
+      return Promise.resolve({
+        blob: {
+          mimeType: 'image/cat',
+          data: new Array(2)
+        }
+      });
+    }
+
+    async isPanTiltZoomPermissionGranted() {
+      if (!this.panTiltZoomPermissionStatus_) {
+        this.panTiltZoomPermissionStatus_ = await navigator.permissions.query({
+          name: "camera",
+          panTiltZoom: true
+        });
+      }
+      return this.panTiltZoomPermissionStatus_.state == "granted";
+    }
+
+    state() {
+      return this.state_.state;
+    }
+
+    turnOffBackgroundBlurMode() {
+      this.state_.state.backgroundBlurMode = BackgroundBlurMode.OFF;
+    }
+    turnOnBackgroundBlurMode() {
+      this.state_.state.backgroundBlurMode = BackgroundBlurMode.BLUR;
+    }
+    turnOffSupportedBackgroundBlurModes() {
+      this.state_.state.supportedBackgroundBlurModes = [BackgroundBlurMode.OFF];
+    }
+    turnOnSupportedBackgroundBlurModes() {
+      this.state_.state.supportedBackgroundBlurModes = [BackgroundBlurMode.BLUR];
+    }
+
+    options() {
+      return this.settings_;
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    mockImageCapture: null
+  }
+
+  class ImageCaptureTestChromium {
+
+    constructor() {
+      Object.freeze(this); // Make it immutable.
+    }
+
+    initialize() {
+      if (testInternal.initialized)
+        throw new Error('Call reset() before initialize().');
+
+      testInternal.mockImageCapture = new MockImageCapture;
+      testInternal.initialized = true;
+    }
+    // Resets state of image capture mocks between test runs.
+    async reset() {
+      if (!testInternal.initialized)
+        throw new Error('Call initialize() before reset().');
+      testInternal.mockImageCapture.reset();
+      testInternal.mockImageCapture = null;
+      testInternal.initialized = false;
+
+      await new Promise(resolve => setTimeout(resolve, 0));
+    }
+    mockImageCapture() {
+      return testInternal.mockImageCapture;
+    }
+  }
+
+  return ImageCaptureTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/mock-managed-config.js b/testing/web-platform/tests/resources/chromium/mock-managed-config.js
new file mode 100644
index 0000000000..c9980e1285
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-managed-config.js
@@ -0,0 +1,91 @@
+'use strict'
+
+import{ManagedConfigurationObserverRemote, ManagedConfigurationService, ManagedConfigurationServiceReceiver} from '/gen/third_party/blink/public/mojom/device/device.mojom.m.js';
+
+
+self.ManagedConfigTest = (() => {
+  // Class that mocks ManagedConfigurationService interface defined in
+  // https://source.chromium.org/chromium/chromium/src/third_party/blink/public/mojom/device/device.mojom
+  class MockManagedConfig {
+    constructor() {
+      this.receiver_ = new ManagedConfigurationServiceReceiver(this);
+      this.interceptor_ = new MojoInterfaceInterceptor(
+          ManagedConfigurationService.$interfaceName);
+      this.interceptor_.oninterfacerequest = e =>
+          this.receiver_.$.bindHandle(e.handle);
+      this.interceptor_.start();
+      this.subscription_ = null;
+      this.reset();
+    }
+
+    reset() {
+      this.configuration_ = null;
+      this.onObserverAdd_ = null;
+    }
+
+    async getManagedConfiguration(keys) {
+      if (this.configuration_ === null) {
+        return {};
+      }
+
+      return {
+        configurations: Object.keys(this.configuration_)
+                            .filter(key => keys.includes(key))
+                            .reduce(
+                                (obj, key) => {
+                                  obj[key] =
+                                      JSON.stringify(this.configuration_[key]);
+                                  return obj;
+                                },
+                                {})
+      };
+    }
+
+    subscribeToManagedConfiguration(remote) {
+      this.subscription_ = remote;
+      if (this.onObserverAdd_ !== null) {
+        this.onObserverAdd_();
+      }
+    }
+
+    setManagedConfig(value) {
+      this.configuration_ = value;
+      if (this.subscription_ !== null) {
+        this.subscription_.onConfigurationChanged();
+      }
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    mockManagedConfig: null
+  }
+
+  class ManagedConfigTestChromium {
+    constructor() {
+      Object.freeze(this);  // Make it immutable.
+    }
+
+    initialize() {
+      if (testInternal.mockManagedConfig !== null) {
+        testInternal.mockManagedConfig.reset();
+        return;
+      }
+
+      testInternal.mockManagedConfig = new MockManagedConfig;
+      testInternal.initialized = true;
+    }
+
+    setManagedConfig(config) {
+      testInternal.mockManagedConfig.setManagedConfig(config);
+    }
+
+    async nextObserverAdded() {
+      await new Promise(resolve => {
+        testInternal.mockManagedConfig.onObserverAdd_ = resolve;
+      });
+    }
+  }
+
+  return ManagedConfigTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/mock-pressure-service.js b/testing/web-platform/tests/resources/chromium/mock-pressure-service.js
new file mode 100644
index 0000000000..02d10f856a
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-pressure-service.js
@@ -0,0 +1,134 @@
+import {PressureManager, PressureManagerReceiver, PressureStatus} from '/gen/services/device/public/mojom/pressure_manager.mojom.m.js'
+import {PressureSource, PressureState} from '/gen/services/device/public/mojom/pressure_update.mojom.m.js'
+
+class MockPressureService {
+  constructor() {
+    this.receiver_ = new PressureManagerReceiver(this);
+    this.interceptor_ =
+        new MojoInterfaceInterceptor(PressureManager.$interfaceName);
+    this.interceptor_.oninterfacerequest = e => {
+      this.receiver_.$.bindHandle(e.handle);
+    };
+    this.reset();
+    this.mojomSourceType_ = new Map([['cpu', PressureSource.kCpu]]);
+    this.mojomStateType_ = new Map([
+      ['nominal', PressureState.kNominal], ['fair', PressureState.kFair],
+      ['serious', PressureState.kSerious], ['critical', PressureState.kCritical]
+    ]);
+    this.pressureServiceReadingTimerId_ = null;
+  }
+
+  start() {
+    this.interceptor_.start();
+  }
+
+  stop() {
+    this.stopPlatformCollector();
+    this.receiver_.$.close();
+    this.interceptor_.stop();
+
+    // Wait for an event loop iteration to let any pending mojo commands in
+    // the pressure service finish.
+    return new Promise(resolve => setTimeout(resolve, 0));
+  }
+
+  reset() {
+    this.observers_ = [];
+    this.pressureUpdate_ = null;
+    this.pressureServiceReadingTimerId_ = null;
+    this.pressureStatus_ = PressureStatus.kOk;
+    this.updatesDelivered_ = 0;
+  }
+
+  async addClient(observer, source) {
+    if (this.observers_.indexOf(observer) >= 0)
+      throw new Error('addClient() has already been called');
+
+    // TODO(crbug.com/1342184): Consider other sources.
+    // For now, "cpu" is the only source.
+    if (source !== PressureSource.kCpu)
+      throw new Error('Call addClient() with a wrong PressureSource');
+
+    observer.onConnectionError.addListener(() => {
+      // Remove this observer from observer array.
+      this.observers_.splice(this.observers_.indexOf(observer), 1);
+    });
+    this.observers_.push(observer);
+
+    return {status: this.pressureStatus_};
+  }
+
+  startPlatformCollector(sampleRate) {
+    if (sampleRate === 0)
+      return;
+
+    if (this.pressureServiceReadingTimerId_ != null)
+      this.stopPlatformCollector();
+
+    // The following code for calculating the timestamp was taken from
+    // https://source.chromium.org/chromium/chromium/src/+/main:third_party/
+    // blink/web_tests/http/tests/resources/
+    // geolocation-mock.js;l=131;drc=37a9b6c03b9bda9fcd62fc0e5e8016c278abd31f
+
+    // The new Date().getTime() returns the number of milliseconds since the
+    // UNIX epoch (1970-01-01 00::00:00 UTC), while |internalValue| of the
+    // device.mojom.PressureUpdate represents the value of microseconds since
+    // the Windows FILETIME epoch (1601-01-01 00:00:00 UTC). So add the delta
+    // when sets the |internalValue|. See more info in //base/time/time.h.
+    const windowsEpoch = Date.UTC(1601, 0, 1, 0, 0, 0, 0);
+    const unixEpoch = Date.UTC(1970, 0, 1, 0, 0, 0, 0);
+    // |epochDeltaInMs| equals to base::Time::kTimeTToMicrosecondsOffset.
+    const epochDeltaInMs = unixEpoch - windowsEpoch;
+
+    const timeout = (1 / sampleRate) * 1000;
+    this.pressureServiceReadingTimerId_ = self.setInterval(() => {
+      if (this.pressureUpdate_ === null || this.observers_.length === 0)
+        return;
+      this.pressureUpdate_.timestamp = {
+        internalValue: BigInt((new Date().getTime() + epochDeltaInMs) * 1000)
+      };
+      for (let observer of this.observers_)
+        observer.onPressureUpdated(this.pressureUpdate_);
+      this.updatesDelivered_++;
+    }, timeout);
+  }
+
+  stopPlatformCollector() {
+    if (this.pressureServiceReadingTimerId_ != null) {
+      self.clearInterval(this.pressureServiceReadingTimerId_);
+      this.pressureServiceReadingTimerId_ = null;
+    }
+    this.updatesDelivered_ = 0;
+  }
+
+  updatesDelivered() {
+    return this.updatesDelivered_;
+  }
+
+  setPressureUpdate(source, state) {
+    if (!this.mojomSourceType_.has(source))
+      throw new Error(`PressureSource '${source}' is invalid`);
+
+    if (!this.mojomStateType_.has(state))
+      throw new Error(`PressureState '${state}' is invalid`);
+
+    this.pressureUpdate_ = {
+      source: this.mojomSourceType_.get(source),
+      state: this.mojomStateType_.get(state),
+    };
+  }
+
+  setExpectedFailure(expectedException) {
+    assert_true(
+        expectedException instanceof DOMException,
+        'setExpectedFailure() expects a DOMException instance');
+    if (expectedException.name === 'NotSupportedError') {
+      this.pressureStatus_ = PressureStatus.kNotSupported;
+    } else {
+      throw new TypeError(
+          `Unexpected DOMException '${expectedException.name}'`);
+    }
+  }
+}
+
+export const mockPressureService = new MockPressureService();
diff --git a/testing/web-platform/tests/resources/chromium/mock-pressure-service.js.headers b/testing/web-platform/tests/resources/chromium/mock-pressure-service.js.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-pressure-service.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
diff --git a/testing/web-platform/tests/resources/chromium/mock-subapps.js b/testing/web-platform/tests/resources/chromium/mock-subapps.js
new file mode 100644
index 0000000000..b81936713b
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-subapps.js
@@ -0,0 +1,89 @@
+'use strict';
+
+import {SubAppsService, SubAppsServiceReceiver, SubAppsServiceResultCode} from '/gen/third_party/blink/public/mojom/subapps/sub_apps_service.mojom.m.js';
+
+self.SubAppsServiceTest = (() => {
+  // Class that mocks SubAppsService interface defined in /third_party/blink/public/mojom/subapps/sub_apps_service.mojom
+
+  class MockSubAppsService {
+    constructor() {
+      this.interceptor_ =
+        new MojoInterfaceInterceptor(SubAppsService.$interfaceName);
+      this.receiver_ = new SubAppsServiceReceiver(this);
+      this.interceptor_.oninterfacerequest =
+        e => this.receiver_.$.bindHandle(e.handle);
+      this.interceptor_.start();
+    }
+
+    reset() {
+      this.interceptor_.stop();
+      this.receiver_.$.close();
+    }
+
+    add(sub_apps) {
+      return Promise.resolve({
+        result: testInternal.addCallReturnValue,
+      });
+    }
+
+    list() {
+      return Promise.resolve({
+        result: {
+          resultCode: testInternal.serviceResultCode,
+          subAppsList: testInternal.listCallReturnValue,
+        }
+      });
+    }
+
+    remove() {
+      return Promise.resolve({
+        result: testInternal.removeCallReturnValue,
+      });
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    mockSubAppsService: null,
+    serviceResultCode: 0,
+    addCallReturnValue: [],
+    listCallReturnValue: [],
+    removeCallReturnValue: [],
+  }
+
+  class SubAppsServiceTestChromium {
+    constructor() {
+      Object.freeze(this);  // Make it immutable.
+    }
+
+    initialize(service_result_code, add_call_return_value, list_call_return_value, remove_call_return_value) {
+      if (!testInternal.initialized) {
+        testInternal = {
+          mockSubAppsService: new MockSubAppsService(),
+          initialized: true,
+          serviceResultCode: service_result_code,
+          addCallReturnValue: add_call_return_value,
+          listCallReturnValue: list_call_return_value,
+          removeCallReturnValue: remove_call_return_value,
+        };
+      };
+    }
+
+    async reset() {
+      if (testInternal.initialized) {
+        testInternal.mockSubAppsService.reset();
+        testInternal = {
+          mockSubAppsService: null,
+          initialized: false,
+          serviceResultCode: 0,
+          addCallReturnValue: [],
+          listCallReturnValue: [],
+          removeCallReturnValue: [],
+        };
+        await new Promise(resolve => setTimeout(resolve, 0));
+      }
+    }
+  }
+
+  return SubAppsServiceTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/mock-textdetection.js b/testing/web-platform/tests/resources/chromium/mock-textdetection.js
new file mode 100644
index 0000000000..52ca987e28
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-textdetection.js
@@ -0,0 +1,92 @@
+import {TextDetection, TextDetectionReceiver} from '/gen/services/shape_detection/public/mojom/textdetection.mojom.m.js';
+
+self.TextDetectionTest = (() => {
+  // Class that mocks TextDetection interface defined in
+  // https://cs.chromium.org/chromium/src/services/shape_detection/public/mojom/textdetection.mojom
+  class MockTextDetection {
+    constructor() {
+      this.receiver_ = new TextDetectionReceiver(this);
+      this.interceptor_ =
+          new MojoInterfaceInterceptor(TextDetection.$interfaceName);
+      this.interceptor_.oninterfacerequest =
+          e => this.receiver_.$.bindHandle(e.handle);
+      this.interceptor_.start();
+    }
+
+    detect(bitmapData) {
+      this.bufferData_ =
+          new Uint32Array(getArrayBufferFromBigBuffer(bitmapData.pixelData));
+      return Promise.resolve({
+        results: [
+          {
+            rawValue : "cats",
+            boundingBox: { x: 1.0, y: 1.0, width: 100.0, height: 100.0 },
+            cornerPoints: [
+              { x: 1.0, y: 1.0 },
+              { x: 101.0, y: 1.0 },
+              { x: 101.0, y: 101.0 },
+              { x: 1.0, y: 101.0 }
+            ]
+          },
+          {
+            rawValue : "dogs",
+            boundingBox: { x: 2.0, y: 2.0, width: 50.0, height: 50.0 },
+            cornerPoints: [
+              { x: 2.0, y: 2.0 },
+              { x: 52.0, y: 2.0 },
+              { x: 52.0, y: 52.0 },
+              { x: 2.0, y: 52.0 }
+            ]
+          },
+        ],
+      });
+    }
+
+    getFrameData() {
+      return this.bufferData_;
+    }
+
+    reset() {
+      this.receiver_.$.close();
+      this.interceptor_.stop();
+    }
+
+  }
+
+  let testInternal = {
+    initialized: false,
+    MockTextDetection: null
+  }
+
+  class TextDetectionTestChromium {
+    constructor() {
+      Object.freeze(this); // Make it immutable.
+    }
+
+    initialize() {
+      if (testInternal.initialized)
+        throw new Error('Call reset() before initialize().');
+
+      testInternal.MockTextDetection = new MockTextDetection;
+      testInternal.initialized = true;
+    }
+
+    // Resets state of text detection mocks between test runs.
+    async reset() {
+      if (!testInternal.initialized)
+        throw new Error('Call initialize() before reset().');
+      testInternal.MockTextDetection.reset();
+      testInternal.MockTextDetection = null;
+      testInternal.initialized = false;
+
+      await new Promise(resolve => setTimeout(resolve, 0));
+    }
+
+    MockTextDetection() {
+      return testInternal.MockTextDetection;
+    }
+  }
+
+  return TextDetectionTestChromium;
+
+})();
diff --git a/testing/web-platform/tests/resources/chromium/mock-textdetection.js.headers b/testing/web-platform/tests/resources/chromium/mock-textdetection.js.headers
new file mode 100644
index 0000000000..6c61a34a4e
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/mock-textdetection.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
\ No newline at end of file
diff --git a/testing/web-platform/tests/resources/chromium/nfc-mock.js b/testing/web-platform/tests/resources/chromium/nfc-mock.js
new file mode 100644
index 0000000000..31a71b9e22
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/nfc-mock.js
@@ -0,0 +1,437 @@
+import {NDEFErrorType, NDEFRecordTypeCategory, NFC, NFCReceiver} from '/gen/services/device/public/mojom/nfc.mojom.m.js';
+
+// Converts between NDEFMessageInit https://w3c.github.io/web-nfc/#dom-ndefmessage
+// and mojom.NDEFMessage structure, so that watch function can be tested.
+function toMojoNDEFMessage(message) {
+  let ndefMessage = {data: []};
+  for (let record of message.records) {
+    ndefMessage.data.push(toMojoNDEFRecord(record));
+  }
+  return ndefMessage;
+}
+
+function toMojoNDEFRecord(record) {
+  let nfcRecord = {};
+  // Simply checks the existence of ':' to decide whether it's an external
+  // type or a local type. As a mock, no need to really implement the validation
+  // algorithms for them.
+  if (record.recordType.startsWith(':')) {
+    nfcRecord.category = NDEFRecordTypeCategory.kLocal;
+  } else if (record.recordType.search(':') != -1) {
+    nfcRecord.category = NDEFRecordTypeCategory.kExternal;
+  } else {
+    nfcRecord.category = NDEFRecordTypeCategory.kStandardized;
+  }
+  nfcRecord.recordType = record.recordType;
+  nfcRecord.mediaType = record.mediaType;
+  nfcRecord.id = record.id;
+  if (record.recordType == 'text') {
+    nfcRecord.encoding = record.encoding == null? 'utf-8': record.encoding;
+    nfcRecord.lang = record.lang == null? 'en': record.lang;
+  }
+  nfcRecord.data = toByteArray(record.data);
+  if (record.data != null && record.data.records !== undefined) {
+    // |record.data| may be an NDEFMessageInit, i.e. the payload is a message.
+    nfcRecord.payloadMessage = toMojoNDEFMessage(record.data);
+  }
+  return nfcRecord;
+}
+
+// Converts JS objects to byte array.
+function toByteArray(data) {
+  if (data instanceof ArrayBuffer)
+    return new Uint8Array(data);
+  else if (ArrayBuffer.isView(data))
+    return new Uint8Array(data.buffer, data.byteOffset, data.byteLength);
+
+  let byteArray = new Uint8Array(0);
+  let tmpData = data;
+  if (typeof tmpData === 'object' || typeof tmpData === 'number')
+    tmpData = JSON.stringify(tmpData);
+
+  if (typeof tmpData === 'string')
+    byteArray = new TextEncoder().encode(tmpData);
+
+  return byteArray;
+}
+
+// Compares NDEFRecords that were provided / received by the mock service.
+// TODO: Use different getters to get received record data,
+// see spec changes at https://github.com/w3c/web-nfc/pull/243.
+self.compareNDEFRecords = function(providedRecord, receivedRecord) {
+  assert_equals(providedRecord.recordType, receivedRecord.recordType);
+
+  if (providedRecord.id === undefined) {
+    assert_equals(null, receivedRecord.id);
+  } else {
+    assert_equals(providedRecord.id, receivedRecord.id);
+  }
+
+  if (providedRecord.mediaType === undefined) {
+    assert_equals(null, receivedRecord.mediaType);
+  } else {
+    assert_equals(providedRecord.mediaType, receivedRecord.mediaType);
+  }
+
+  assert_not_equals(providedRecord.recordType, 'empty');
+
+  if (providedRecord.recordType == 'text') {
+    assert_equals(
+        providedRecord.encoding == null? 'utf-8': providedRecord.encoding,
+        receivedRecord.encoding);
+    assert_equals(providedRecord.lang == null? 'en': providedRecord.lang,
+                  receivedRecord.lang);
+  } else {
+    assert_equals(null, receivedRecord.encoding);
+    assert_equals(null, receivedRecord.lang);
+  }
+
+  assert_array_equals(toByteArray(providedRecord.data),
+                      new Uint8Array(receivedRecord.data));
+}
+
+// Compares NDEFWriteOptions structures that were provided to API and
+// received by the mock mojo service.
+self.assertNDEFWriteOptionsEqual = function(provided, received) {
+  if (provided.overwrite !== undefined)
+    assert_equals(provided.overwrite, !!received.overwrite);
+  else
+    assert_equals(!!received.overwrite, true);
+}
+
+// Compares NDEFReaderOptions structures that were provided to API and
+// received by the mock mojo service.
+self.assertNDEFReaderOptionsEqual = function(provided, received) {
+  if (provided.url !== undefined)
+    assert_equals(provided.url, received.url);
+  else
+    assert_equals(received.url, '');
+
+  if (provided.mediaType !== undefined)
+    assert_equals(provided.mediaType, received.mediaType);
+  else
+    assert_equals(received.mediaType, '');
+
+  if (provided.recordType !== undefined) {
+    assert_equals(provided.recordType, received.recordType);
+  }
+}
+
+function createNDEFError(type) {
+  return {error: (type != null ? {errorType: type, errorMessage: ''} : null)};
+}
+
+self.WebNFCTest = (() => {
+  class MockNFC {
+    constructor() {
+      this.receiver_ = new NFCReceiver(this);
+
+      this.interceptor_ = new MojoInterfaceInterceptor(NFC.$interfaceName);
+      this.interceptor_.oninterfacerequest = e => {
+        if (this.should_close_pipe_on_request_)
+          e.handle.close();
+        else
+          this.receiver_.$.bindHandle(e.handle);
+      }
+
+      this.interceptor_.start();
+
+      this.hw_status_ = NFCHWStatus.ENABLED;
+      this.pushed_message_ = null;
+      this.pending_write_options_ = null;
+      this.pending_push_promise_func_ = null;
+      this.push_completed_ = true;
+      this.pending_make_read_only_promise_func_ = null;
+      this.make_read_only_completed_ = true;
+      this.client_ = null;
+      this.watchers_ = [];
+      this.reading_messages_ = [];
+      this.operations_suspended_ = false;
+      this.is_formatted_tag_ = false;
+      this.data_transfer_failed_ = false;
+      this.should_close_pipe_on_request_ = false;
+    }
+
+    // NFC delegate functions.
+    async push(message, options) {
+      const error = this.getHWError();
+      if (error)
+        return error;
+      // Cancels previous pending push operation.
+      if (this.pending_push_promise_func_) {
+        this.cancelPendingPushOperation();
+      }
+
+      this.pushed_message_ = message;
+      this.pending_write_options_ = options;
+      return new Promise(resolve => {
+        if (this.operations_suspended_ || !this.push_completed_) {
+          // Leaves the push pending.
+          this.pending_push_promise_func_ = resolve;
+        } else if (this.is_formatted_tag_ && !options.overwrite) {
+          // Resolves with NotAllowedError if there are NDEF records on the device
+          // and overwrite is false.
+          resolve(createNDEFError(NDEFErrorType.NOT_ALLOWED));
+        } else if (this.data_transfer_failed_) {
+          // Resolves with NetworkError if data transfer fails.
+          resolve(createNDEFError(NDEFErrorType.IO_ERROR));
+        } else {
+          resolve(createNDEFError(null));
+        }
+      });
+    }
+
+    async cancelPush() {
+      this.cancelPendingPushOperation();
+      return createNDEFError(null);
+    }
+
+    async makeReadOnly(options) {
+      const error = this.getHWError();
+      if (error)
+        return error;
+      // Cancels previous pending makeReadOnly operation.
+      if (this.pending_make_read_only_promise_func_) {
+        this.cancelPendingMakeReadOnlyOperation();
+      }
+
+      if (this.operations_suspended_ || !this.make_read_only_completed_) {
+        // Leaves the makeReadOnly pending.
+        return new Promise(resolve => {
+          this.pending_make_read_only_promise_func_ = resolve;
+        });
+      } else if (this.data_transfer_failed_) {
+        // Resolves with NetworkError if data transfer fails.
+        return createNDEFError(NDEFErrorType.IO_ERROR);
+      } else {
+        return createNDEFError(null);
+      }
+    }
+
+    async cancelMakeReadOnly() {
+      this.cancelPendingMakeReadOnlyOperation();
+      return createNDEFError(null);
+    }
+
+    setClient(client) {
+      this.client_ = client;
+    }
+
+    async watch(id) {
+      assert_true(id > 0);
+      const error = this.getHWError();
+      if (error) {
+        return error;
+      }
+
+      this.watchers_.push({id: id});
+      // Ignores reading if NFC operation is suspended
+      // or the NFC tag does not expose NDEF technology.
+      if (!this.operations_suspended_) {
+        // Triggers onWatch if the new watcher matches existing messages.
+        for (let message of this.reading_messages_) {
+          this.client_.onWatch(
+              [id], fake_tag_serial_number, toMojoNDEFMessage(message));
+        }
+      }
+
+      return createNDEFError(null);
+    }
+
+    cancelWatch(id) {
+      let index = this.watchers_.findIndex(value => value.id === id);
+      if (index !== -1) {
+        this.watchers_.splice(index, 1);
+      }
+    }
+
+    getHWError() {
+      if (this.hw_status_ === NFCHWStatus.DISABLED)
+        return createNDEFError(NDEFErrorType.NOT_READABLE);
+      if (this.hw_status_ === NFCHWStatus.NOT_SUPPORTED)
+        return createNDEFError(NDEFErrorType.NOT_SUPPORTED);
+      return null;
+    }
+
+    setHWStatus(status) {
+      this.hw_status_ = status;
+    }
+
+    pushedMessage() {
+      return this.pushed_message_;
+    }
+
+    writeOptions() {
+      return this.pending_write_options_;
+    }
+
+    watchOptions() {
+      assert_not_equals(this.watchers_.length, 0);
+      return this.watchers_[this.watchers_.length - 1].options;
+    }
+
+    setPendingPushCompleted(result) {
+      this.push_completed_ = result;
+    }
+
+    setPendingMakeReadOnlyCompleted(result) {
+      this.make_read_only_completed_ = result;
+    }
+
+    reset() {
+      this.hw_status_ = NFCHWStatus.ENABLED;
+      this.watchers_ = [];
+      this.reading_messages_ = [];
+      this.operations_suspended_ = false;
+      this.cancelPendingPushOperation();
+      this.cancelPendingMakeReadOnlyOperation();
+      this.is_formatted_tag_ = false;
+      this.data_transfer_failed_ = false;
+      this.should_close_pipe_on_request_ = false;
+    }
+
+    cancelPendingPushOperation() {
+      if (this.pending_push_promise_func_) {
+        this.pending_push_promise_func_(
+            createNDEFError(NDEFErrorType.OPERATION_CANCELLED));
+        this.pending_push_promise_func_ = null;
+      }
+
+      this.pushed_message_ = null;
+      this.pending_write_options_ = null;
+      this.push_completed_ = true;
+    }
+
+    cancelPendingMakeReadOnlyOperation() {
+      if (this.pending_make_read_only_promise_func_) {
+        this.pending_make_read_only_promise_func_(
+            createNDEFError(NDEFErrorType.OPERATION_CANCELLED));
+        this.pending_make_read_only_promise_func_ = null;
+      }
+
+      this.make_read_only_completed_ = true;
+    }
+
+    // Sets message that is used to deliver NFC reading updates.
+    setReadingMessage(message) {
+      this.reading_messages_.push(message);
+      // Ignores reading if NFC operation is suspended.
+      if(this.operations_suspended_) return;
+      // when overwrite is false, the write algorithm will read the NFC tag
+      // to determine if it has NDEF records on it.
+      if (this.pending_write_options_ && this.pending_write_options_.overwrite)
+        return;
+      // Triggers onWatch if the new message matches existing watchers.
+      for (let watcher of this.watchers_) {
+        this.client_.onWatch(
+            [watcher.id], fake_tag_serial_number,
+            toMojoNDEFMessage(message));
+      }
+    }
+
+    // Suspends all pending NFC operations. Could be used when web page
+    // visibility is lost.
+    suspendNFCOperations() {
+      this.operations_suspended_ = true;
+    }
+
+    // Resumes all suspended NFC operations.
+    resumeNFCOperations() {
+      this.operations_suspended_ = false;
+      // Resumes pending NFC reading.
+      for (let watcher of this.watchers_) {
+        for (let message of this.reading_messages_) {
+          this.client_.onWatch(
+              [watcher.id], fake_tag_serial_number,
+              toMojoNDEFMessage(message));
+        }
+      }
+      // Resumes pending push operation.
+      if (this.pending_push_promise_func_ && this.push_completed_) {
+        this.pending_push_promise_func_(createNDEFError(null));
+        this.pending_push_promise_func_ = null;
+      }
+      // Resumes pending makeReadOnly operation.
+      if (this.pending_make_read_only_promise_func_ &&
+          this.make_read_only_completed_) {
+        this.pending_make_read_only_promise_func_(createNDEFError(null));
+        this.pending_make_read_only_promise_func_ = null;
+      }
+    }
+
+    // Simulates the device coming in proximity does not expose NDEF technology.
+    simulateNonNDEFTagDiscovered() {
+      // Notify NotSupportedError to all active readers.
+      if (this.watchers_.length != 0) {
+        this.client_.onError({
+          errorType: NDEFErrorType.NOT_SUPPORTED,
+          errorMessage: ''
+        });
+      }
+      // Reject the pending push with NotSupportedError.
+      if (this.pending_push_promise_func_) {
+        this.pending_push_promise_func_(
+            createNDEFError(NDEFErrorType.NOT_SUPPORTED));
+        this.pending_push_promise_func_ = null;
+      }
+      // Reject the pending makeReadOnly with NotSupportedError.
+      if (this.pending_make_read_only_promise_func_) {
+        this.pending_make_read_only_promise_func_(
+            createNDEFError(NDEFErrorType.NOT_SUPPORTED));
+        this.pending_make_read_only_promise_func_ = null;
+      }
+    }
+
+    setIsFormattedTag(isFormatted) {
+      this.is_formatted_tag_ = isFormatted;
+    }
+
+    simulateDataTransferFails() {
+      this.data_transfer_failed_ = true;
+    }
+
+    simulateClosedPipe() {
+      this.should_close_pipe_on_request_ = true;
+    }
+  }
+
+  let testInternal = {
+    initialized: false,
+    mockNFC: null
+  }
+
+  class NFCTestChromium {
+    constructor() {
+      Object.freeze(this); // Makes it immutable.
+    }
+
+    async initialize() {
+      if (testInternal.initialized)
+        throw new Error('Call reset() before initialize().');
+
+      // Grant nfc permissions for Chromium testdriver.
+      await test_driver.set_permission({ name: 'nfc' }, 'granted');
+
+      if (testInternal.mockNFC == null) {
+        testInternal.mockNFC = new MockNFC();
+      }
+      testInternal.initialized = true;
+    }
+
+    // Reuses the nfc mock but resets its state between test runs.
+    async reset() {
+      if (!testInternal.initialized)
+        throw new Error('Call initialize() before reset().');
+      testInternal.mockNFC.reset();
+      testInternal.initialized = false;
+
+      await new Promise(resolve => setTimeout(resolve, 0));
+    }
+
+    getMockNFC() {
+      return testInternal.mockNFC;
+    }
+  }
+
+  return NFCTestChromium;
+})();
diff --git a/testing/web-platform/tests/resources/chromium/web-bluetooth-test.js b/testing/web-platform/tests/resources/chromium/web-bluetooth-test.js
new file mode 100644
index 0000000000..ecea5e760c
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/web-bluetooth-test.js
@@ -0,0 +1,629 @@
+'use strict';
+
+const content = {};
+const bluetooth = {};
+const MOJO_CHOOSER_EVENT_TYPE_MAP = {};
+
+function toMojoCentralState(state) {
+  switch (state) {
+    case 'absent':
+      return bluetooth.mojom.CentralState.ABSENT;
+    case 'powered-off':
+      return bluetooth.mojom.CentralState.POWERED_OFF;
+    case 'powered-on':
+      return bluetooth.mojom.CentralState.POWERED_ON;
+    default:
+      throw `Unsupported value ${state} for state.`;
+  }
+}
+
+// Converts bluetooth.mojom.WriteType to a string. If |writeType| is
+// invalid, this method will throw.
+function writeTypeToString(writeType) {
+  switch (writeType) {
+    case bluetooth.mojom.WriteType.kNone:
+      return 'none';
+    case bluetooth.mojom.WriteType.kWriteDefaultDeprecated:
+      return 'default-deprecated';
+    case bluetooth.mojom.WriteType.kWriteWithResponse:
+      return 'with-response';
+    case bluetooth.mojom.WriteType.kWriteWithoutResponse:
+      return 'without-response';
+    default:
+      throw `Unknown bluetooth.mojom.WriteType: ${writeType}`;
+  }
+}
+
+// Canonicalizes UUIDs and converts them to Mojo UUIDs.
+function canonicalizeAndConvertToMojoUUID(uuids) {
+  let canonicalUUIDs = uuids.map(val => ({uuid: BluetoothUUID.getService(val)}));
+  return canonicalUUIDs;
+}
+
+// Converts WebIDL a record<DOMString, BufferSource> to a map<K, array<uint8>> to
+// use for Mojo, where the value for K is calculated using keyFn.
+function convertToMojoMap(record, keyFn, isNumberKey = false) {
+  let map = new Map();
+  for (const [key, value] of Object.entries(record)) {
+    let buffer = ArrayBuffer.isView(value) ? value.buffer : value;
+    if (isNumberKey) {
+      let numberKey = parseInt(key);
+      if (Number.isNaN(numberKey))
+        throw `Map key ${key} is not a number`;
+      map.set(keyFn(numberKey), Array.from(new Uint8Array(buffer)));
+      continue;
+    }
+    map.set(keyFn(key), Array.from(new Uint8Array(buffer)));
+  }
+  return map;
+}
+
+function ArrayToMojoCharacteristicProperties(arr) {
+  const struct = {};
+  arr.forEach(property => { struct[property] = true; });
+  return struct;
+}
+
+class FakeBluetooth {
+  constructor() {
+    this.fake_bluetooth_ptr_ = new bluetooth.mojom.FakeBluetoothRemote();
+    this.fake_bluetooth_ptr_.$.bindNewPipeAndPassReceiver().bindInBrowser('process');
+    this.fake_central_ = null;
+  }
+
+  // Set it to indicate whether the platform supports BLE. For example,
+  // Windows 7 is a platform that doesn't support Low Energy. On the other
+  // hand Windows 10 is a platform that does support LE, even if there is no
+  // Bluetooth radio present.
+  async setLESupported(supported) {
+    if (typeof supported !== 'boolean') throw 'Type Not Supported';
+    await this.fake_bluetooth_ptr_.setLESupported(supported);
+  }
+
+  // Returns a promise that resolves with a FakeCentral that clients can use
+  // to simulate events that a device in the Central/Observer role would
+  // receive as well as monitor the operations performed by the device in the
+  // Central/Observer role.
+  // Calls sets LE as supported.
+  //
+  // A "Central" object would allow its clients to receive advertising events
+  // and initiate connections to peripherals i.e. operations of two roles
+  // defined by the Bluetooth Spec: Observer and Central.
+  // See Bluetooth 4.2 Vol 3 Part C 2.2.2 "Roles when Operating over an
+  // LE Physical Transport".
+  async simulateCentral({state}) {
+    if (this.fake_central_)
+      throw 'simulateCentral() should only be called once';
+
+    await this.setLESupported(true);
+
+    let {fakeCentral: fake_central_ptr} =
+      await this.fake_bluetooth_ptr_.simulateCentral(
+        toMojoCentralState(state));
+    this.fake_central_ = new FakeCentral(fake_central_ptr);
+    return this.fake_central_;
+  }
+
+  // Returns true if there are no pending responses.
+  async allResponsesConsumed() {
+    let {consumed} = await this.fake_bluetooth_ptr_.allResponsesConsumed();
+    return consumed;
+  }
+
+  // Returns a promise that resolves with a FakeChooser that clients can use to
+  // simulate chooser events.
+  async getManualChooser() {
+    if (typeof this.fake_chooser_ === 'undefined') {
+      this.fake_chooser_ = new FakeChooser();
+    }
+    return this.fake_chooser_;
+  }
+}
+
+// FakeCentral allows clients to simulate events that a device in the
+// Central/Observer role would receive as well as monitor the operations
+// performed by the device in the Central/Observer role.
+class FakeCentral {
+  constructor(fake_central_ptr) {
+    this.fake_central_ptr_ = fake_central_ptr;
+    this.peripherals_ = new Map();
+  }
+
+  // Simulates a peripheral with |address|, |name|, |manufacturerData| and
+  // |known_service_uuids| that has already been connected to the system. If the
+  // peripheral existed already it updates its name, manufacturer data, and
+  // known UUIDs. |known_service_uuids| should be an array of
+  // BluetoothServiceUUIDs
+  // https://webbluetoothcg.github.io/web-bluetooth/#typedefdef-bluetoothserviceuuid
+  //
+  // Platforms offer methods to retrieve devices that have already been
+  // connected to the system or weren't connected through the UA e.g. a user
+  // connected a peripheral through the system's settings. This method is
+  // intended to simulate peripherals that those methods would return.
+  async simulatePreconnectedPeripheral(
+      {address, name, manufacturerData = {}, knownServiceUUIDs = []}) {
+    await this.fake_central_ptr_.simulatePreconnectedPeripheral(
+        address, name,
+        convertToMojoMap(manufacturerData, Number, true /* isNumberKey */),
+        canonicalizeAndConvertToMojoUUID(knownServiceUUIDs));
+
+    return this.fetchOrCreatePeripheral_(address);
+  }
+
+  // Simulates an advertisement packet described by |scanResult| being received
+  // from a device. If central is currently scanning, the device will appear on
+  // the list of discovered devices.
+  async simulateAdvertisementReceived(scanResult) {
+    // Create a deep-copy to prevent the original |scanResult| from being
+    // modified when the UUIDs, manufacturer, and service data are converted.
+    let clonedScanResult = JSON.parse(JSON.stringify(scanResult));
+
+    if ('uuids' in scanResult.scanRecord) {
+      clonedScanResult.scanRecord.uuids =
+          canonicalizeAndConvertToMojoUUID(scanResult.scanRecord.uuids);
+    }
+
+    // Convert the optional appearance and txPower fields to the corresponding
+    // Mojo structures, since Mojo does not support optional interger values. If
+    // the fields are undefined, set the hasValue field as false and value as 0.
+    // Otherwise, set the hasValue field as true and value with the field value.
+    const has_appearance = 'appearance' in scanResult.scanRecord;
+    clonedScanResult.scanRecord.appearance = {
+      hasValue: has_appearance,
+      value: (has_appearance ? scanResult.scanRecord.appearance : 0)
+    }
+
+    const has_tx_power = 'txPower' in scanResult.scanRecord;
+    clonedScanResult.scanRecord.txPower = {
+      hasValue: has_tx_power,
+      value: (has_tx_power ? scanResult.scanRecord.txPower : 0)
+    }
+
+    // Convert manufacturerData from a record<DOMString, BufferSource> into a
+    // map<uint8, array<uint8>> for Mojo.
+    if ('manufacturerData' in scanResult.scanRecord) {
+      clonedScanResult.scanRecord.manufacturerData = convertToMojoMap(
+          scanResult.scanRecord.manufacturerData, Number,
+          true /* isNumberKey */);
+    }
+
+    // Convert serviceData from a record<DOMString, BufferSource> into a
+    // map<string, array<uint8>> for Mojo.
+    if ('serviceData' in scanResult.scanRecord) {
+      clonedScanResult.scanRecord.serviceData.serviceData = convertToMojoMap(
+          scanResult.scanRecord.serviceData, BluetoothUUID.getService,
+          false /* isNumberKey */);
+    }
+
+    await this.fake_central_ptr_.simulateAdvertisementReceived(
+        clonedScanResult);
+
+    return this.fetchOrCreatePeripheral_(clonedScanResult.deviceAddress);
+  }
+
+  // Simulates a change in the central device described by |state|. For example,
+  // setState('powered-off') can be used to simulate the central device powering
+  // off.
+  //
+  // This method should be used for any central state changes after
+  // simulateCentral() has been called to create a FakeCentral object.
+  async setState(state) {
+    await this.fake_central_ptr_.setState(toMojoCentralState(state));
+  }
+
+  // Create a fake_peripheral object from the given address.
+  fetchOrCreatePeripheral_(address) {
+    let peripheral = this.peripherals_.get(address);
+    if (peripheral === undefined) {
+      peripheral = new FakePeripheral(address, this.fake_central_ptr_);
+      this.peripherals_.set(address, peripheral);
+    }
+    return peripheral;
+  }
+}
+
+class FakePeripheral {
+  constructor(address, fake_central_ptr) {
+    this.address = address;
+    this.fake_central_ptr_ = fake_central_ptr;
+  }
+
+  // Adds a fake GATT Service with |uuid| to be discovered when discovering
+  // the peripheral's GATT Attributes. Returns a FakeRemoteGATTService
+  // corresponding to this service. |uuid| should be a BluetoothServiceUUIDs
+  // https://webbluetoothcg.github.io/web-bluetooth/#typedefdef-bluetoothserviceuuid
+  async addFakeService({uuid}) {
+    let {serviceId: service_id} = await this.fake_central_ptr_.addFakeService(
+      this.address, {uuid: BluetoothUUID.getService(uuid)});
+
+    if (service_id === null) throw 'addFakeService failed';
+
+    return new FakeRemoteGATTService(
+      service_id, this.address, this.fake_central_ptr_);
+  }
+
+  // Sets the next GATT Connection request response to |code|. |code| could be
+  // an HCI Error Code from BT 4.2 Vol 2 Part D 1.3 List Of Error Codes or a
+  // number outside that range returned by specific platforms e.g. Android
+  // returns 0x101 to signal a GATT failure
+  // https://developer.android.com/reference/android/bluetooth/BluetoothGatt.html#GATT_FAILURE
+  async setNextGATTConnectionResponse({code}) {
+    let {success} =
+      await this.fake_central_ptr_.setNextGATTConnectionResponse(
+        this.address, code);
+
+    if (success !== true) throw 'setNextGATTConnectionResponse failed.';
+  }
+
+  // Sets the next GATT Discovery request response for peripheral with
+  // |address| to |code|. |code| could be an HCI Error Code from
+  // BT 4.2 Vol 2 Part D 1.3 List Of Error Codes or a number outside that
+  // range returned by specific platforms e.g. Android returns 0x101 to signal
+  // a GATT failure
+  // https://developer.android.com/reference/android/bluetooth/BluetoothGatt.html#GATT_FAILURE
+  //
+  // The following procedures defined at BT 4.2 Vol 3 Part G Section 4.
+  // "GATT Feature Requirements" are used to discover attributes of the
+  // GATT Server:
+  //  - Primary Service Discovery
+  //  - Relationship Discovery
+  //  - Characteristic Discovery
+  //  - Characteristic Descriptor Discovery
+  // This method aims to simulate the response once all of these procedures
+  // have completed or if there was an error during any of them.
+  async setNextGATTDiscoveryResponse({code}) {
+    let {success} =
+      await this.fake_central_ptr_.setNextGATTDiscoveryResponse(
+        this.address, code);
+
+    if (success !== true) throw 'setNextGATTDiscoveryResponse failed.';
+  }
+
+  // Simulates a GATT disconnection from the peripheral with |address|.
+  async simulateGATTDisconnection() {
+    let {success} =
+      await this.fake_central_ptr_.simulateGATTDisconnection(this.address);
+
+    if (success !== true) throw 'simulateGATTDisconnection failed.';
+  }
+
+  // Simulates an Indication from the peripheral's GATT `Service Changed`
+  // Characteristic from BT 4.2 Vol 3 Part G 7.1. This Indication is signaled
+  // when services, characteristics, or descriptors are changed, added, or
+  // removed.
+  //
+  // The value for `Service Changed` is a range of attribute handles that have
+  // changed. However, this testing specification works at an abstracted
+  // level and does not expose setting attribute handles when adding
+  // attributes. Consequently, this simulate method should include the full
+  // range of all the peripheral's attribute handle values.
+  async simulateGATTServicesChanged() {
+    let {success} =
+      await this.fake_central_ptr_.simulateGATTServicesChanged(this.address);
+
+    if (success !== true) throw 'simulateGATTServicesChanged failed.';
+  }
+}
+
+class FakeRemoteGATTService {
+  constructor(service_id, peripheral_address, fake_central_ptr) {
+    this.service_id_ = service_id;
+    this.peripheral_address_ = peripheral_address;
+    this.fake_central_ptr_ = fake_central_ptr;
+  }
+
+  // Adds a fake GATT Characteristic with |uuid| and |properties|
+  // to this fake service. The characteristic will be found when discovering
+  // the peripheral's GATT Attributes. Returns a FakeRemoteGATTCharacteristic
+  // corresponding to the added characteristic.
+  async addFakeCharacteristic({uuid, properties}) {
+    let {characteristicId: characteristic_id} =
+        await this.fake_central_ptr_.addFakeCharacteristic(
+            {uuid: BluetoothUUID.getCharacteristic(uuid)},
+            ArrayToMojoCharacteristicProperties(properties),
+            this.service_id_,
+            this.peripheral_address_);
+
+    if (characteristic_id === null) throw 'addFakeCharacteristic failed';
+
+    return new FakeRemoteGATTCharacteristic(
+      characteristic_id, this.service_id_,
+      this.peripheral_address_, this.fake_central_ptr_);
+  }
+
+  // Removes the fake GATT service from its fake peripheral.
+  async remove() {
+    let {success} =
+        await this.fake_central_ptr_.removeFakeService(
+            this.service_id_,
+            this.peripheral_address_);
+
+    if (!success) throw 'remove failed';
+  }
+}
+
+class FakeRemoteGATTCharacteristic {
+  constructor(characteristic_id, service_id, peripheral_address,
+      fake_central_ptr) {
+    this.ids_ = [characteristic_id, service_id, peripheral_address];
+    this.descriptors_ = [];
+    this.fake_central_ptr_ = fake_central_ptr;
+  }
+
+  // Adds a fake GATT Descriptor with |uuid| to be discovered when
+  // discovering the peripheral's GATT Attributes. Returns a
+  // FakeRemoteGATTDescriptor corresponding to this descriptor. |uuid| should
+  // be a BluetoothDescriptorUUID
+  // https://webbluetoothcg.github.io/web-bluetooth/#typedefdef-bluetoothdescriptoruuid
+  async addFakeDescriptor({uuid}) {
+    let {descriptorId: descriptor_id} =
+        await this.fake_central_ptr_.addFakeDescriptor(
+            {uuid: BluetoothUUID.getDescriptor(uuid)}, ...this.ids_);
+
+    if (descriptor_id === null) throw 'addFakeDescriptor failed';
+
+    let fake_descriptor = new FakeRemoteGATTDescriptor(
+      descriptor_id, ...this.ids_, this.fake_central_ptr_);
+    this.descriptors_.push(fake_descriptor);
+
+    return fake_descriptor;
+  }
+
+  // Sets the next read response for characteristic to |code| and |value|.
+  // |code| could be a GATT Error Response from
+  // BT 4.2 Vol 3 Part F 3.4.1.1 Error Response or a number outside that range
+  // returned by specific platforms e.g. Android returns 0x101 to signal a GATT
+  // failure.
+  // https://developer.android.com/reference/android/bluetooth/BluetoothGatt.html#GATT_FAILURE
+  async setNextReadResponse(gatt_code, value=null) {
+    if (gatt_code === 0 && value === null) {
+      throw '|value| can\'t be null if read should success.';
+    }
+    if (gatt_code !== 0 && value !== null) {
+      throw '|value| must be null if read should fail.';
+    }
+
+    let {success} =
+      await this.fake_central_ptr_.setNextReadCharacteristicResponse(
+        gatt_code, value, ...this.ids_);
+
+    if (!success) throw 'setNextReadCharacteristicResponse failed';
+  }
+
+  // Sets the next write response for this characteristic to |code|. If
+  // writing to a characteristic that only supports 'write_without_response'
+  // the set response will be ignored.
+  // |code| could be a GATT Error Response from
+  // BT 4.2 Vol 3 Part F 3.4.1.1 Error Response or a number outside that range
+  // returned by specific platforms e.g. Android returns 0x101 to signal a GATT
+  // failure.
+  async setNextWriteResponse(gatt_code) {
+    let {success} =
+      await this.fake_central_ptr_.setNextWriteCharacteristicResponse(
+        gatt_code, ...this.ids_);
+
+    if (!success) throw 'setNextWriteCharacteristicResponse failed';
+  }
+
+  // Sets the next subscribe to notifications response for characteristic with
+  // |characteristic_id| in |service_id| and in |peripheral_address| to
+  // |code|. |code| could be a GATT Error Response from BT 4.2 Vol 3 Part F
+  // 3.4.1.1 Error Response or a number outside that range returned by
+  // specific platforms e.g. Android returns 0x101 to signal a GATT failure.
+  async setNextSubscribeToNotificationsResponse(gatt_code) {
+    let {success} =
+      await this.fake_central_ptr_.setNextSubscribeToNotificationsResponse(
+        gatt_code, ...this.ids_);
+
+    if (!success) throw 'setNextSubscribeToNotificationsResponse failed';
+  }
+
+  // Sets the next unsubscribe to notifications response for characteristic with
+  // |characteristic_id| in |service_id| and in |peripheral_address| to
+  // |code|. |code| could be a GATT Error Response from BT 4.2 Vol 3 Part F
+  // 3.4.1.1 Error Response or a number outside that range returned by
+  // specific platforms e.g. Android returns 0x101 to signal a GATT failure.
+  async setNextUnsubscribeFromNotificationsResponse(gatt_code) {
+    let {success} =
+      await this.fake_central_ptr_.setNextUnsubscribeFromNotificationsResponse(
+        gatt_code, ...this.ids_);
+
+    if (!success) throw 'setNextUnsubscribeToNotificationsResponse failed';
+  }
+
+  // Returns true if notifications from the characteristic have been subscribed
+  // to.
+  async isNotifying() {
+    let {success, isNotifying} =
+        await this.fake_central_ptr_.isNotifying(...this.ids_);
+
+    if (!success) throw 'isNotifying failed';
+
+    return isNotifying;
+  }
+
+  // Gets the last successfully written value to the characteristic and its
+  // write type. Write type is one of 'none', 'default-deprecated',
+  // 'with-response', 'without-response'. Returns {lastValue: null,
+  // lastWriteType: 'none'} if no value has yet been written to the
+  // characteristic.
+  async getLastWrittenValue() {
+    let {success, value, writeType} =
+        await this.fake_central_ptr_.getLastWrittenCharacteristicValue(
+            ...this.ids_);
+
+    if (!success) throw 'getLastWrittenCharacteristicValue failed';
+
+    return {lastValue: value, lastWriteType: writeTypeToString(writeType)};
+  }
+
+  // Removes the fake GATT Characteristic from its fake service.
+  async remove() {
+    let {success} =
+        await this.fake_central_ptr_.removeFakeCharacteristic(...this.ids_);
+
+    if (!success) throw 'remove failed';
+  }
+}
+
+class FakeRemoteGATTDescriptor {
+  constructor(descriptor_id,
+              characteristic_id,
+              service_id,
+              peripheral_address,
+              fake_central_ptr) {
+    this.ids_ = [
+      descriptor_id, characteristic_id, service_id, peripheral_address];
+    this.fake_central_ptr_ = fake_central_ptr;
+  }
+
+  // Sets the next read response for descriptor to |code| and |value|.
+  // |code| could be a GATT Error Response from
+  // BT 4.2 Vol 3 Part F 3.4.1.1 Error Response or a number outside that range
+  // returned by specific platforms e.g. Android returns 0x101 to signal a GATT
+  // failure.
+  // https://developer.android.com/reference/android/bluetooth/BluetoothGatt.html#GATT_FAILURE
+  async setNextReadResponse(gatt_code, value=null) {
+    if (gatt_code === 0 && value === null) {
+      throw '|value| cannot be null if read should succeed.';
+    }
+    if (gatt_code !== 0 && value !== null) {
+      throw '|value| must be null if read should fail.';
+    }
+
+    let {success} =
+      await this.fake_central_ptr_.setNextReadDescriptorResponse(
+        gatt_code, value, ...this.ids_);
+
+    if (!success) throw 'setNextReadDescriptorResponse failed';
+  }
+
+  // Sets the next write response for this descriptor to |code|.
+  // |code| could be a GATT Error Response from
+  // BT 4.2 Vol 3 Part F 3.4.1.1 Error Response or a number outside that range
+  // returned by specific platforms e.g. Android returns 0x101 to signal a GATT
+  // failure.
+  async setNextWriteResponse(gatt_code) {
+    let {success} =
+      await this.fake_central_ptr_.setNextWriteDescriptorResponse(
+        gatt_code, ...this.ids_);
+
+    if (!success) throw 'setNextWriteDescriptorResponse failed';
+  }
+
+  // Gets the last successfully written value to the descriptor.
+  // Returns null if no value has yet been written to the descriptor.
+  async getLastWrittenValue() {
+    let {success, value} =
+      await this.fake_central_ptr_.getLastWrittenDescriptorValue(
+          ...this.ids_);
+
+    if (!success) throw 'getLastWrittenDescriptorValue failed';
+
+    return value;
+  }
+
+  // Removes the fake GATT Descriptor from its fake characteristic.
+  async remove() {
+    let {success} =
+        await this.fake_central_ptr_.removeFakeDescriptor(...this.ids_);
+
+    if (!success) throw 'remove failed';
+  }
+}
+
+// FakeChooser allows clients to simulate user actions on a Bluetooth chooser,
+// and records the events produced by the Bluetooth chooser.
+class FakeChooser {
+  constructor() {
+    let fakeBluetoothChooserFactoryRemote =
+        new content.mojom.FakeBluetoothChooserFactoryRemote();
+    fakeBluetoothChooserFactoryRemote.$.bindNewPipeAndPassReceiver().bindInBrowser('process');
+
+    this.fake_bluetooth_chooser_ptr_ =
+        new content.mojom.FakeBluetoothChooserRemote();
+    this.fake_bluetooth_chooser_client_receiver_ =
+        new content.mojom.FakeBluetoothChooserClientReceiver(this);
+    fakeBluetoothChooserFactoryRemote.createFakeBluetoothChooser(
+        this.fake_bluetooth_chooser_ptr_.$.bindNewPipeAndPassReceiver(),
+        this.fake_bluetooth_chooser_client_receiver_.$.associateAndPassRemote());
+
+    this.events_ = new Array();
+    this.event_listener_ = null;
+  }
+
+  // If the chooser has received more events than |numOfEvents| this function
+  // will reject the promise, else it will wait until |numOfEvents| events are
+  // received before resolving with an array of |FakeBluetoothChooserEvent|
+  // objects.
+  async waitForEvents(numOfEvents) {
+    return new Promise(resolve => {
+      if (this.events_.length > numOfEvents) {
+        throw `Asked for ${numOfEvents} event(s), but received ` +
+            `${this.events_.length}.`;
+      }
+
+      this.event_listener_ = () => {
+         if (this.events_.length === numOfEvents) {
+          let result = Array.from(this.events_);
+          this.event_listener_ = null;
+          this.events_ = [];
+          resolve(result);
+        }
+      };
+      this.event_listener_();
+    });
+  }
+
+  async selectPeripheral(peripheral) {
+    if (!(peripheral instanceof FakePeripheral)) {
+      throw '|peripheral| must be an instance of FakePeripheral';
+    }
+    await this.fake_bluetooth_chooser_ptr_.selectPeripheral(peripheral.address);
+  }
+
+  async cancel() {
+    await this.fake_bluetooth_chooser_ptr_.cancel();
+  }
+
+  async rescan() {
+    await this.fake_bluetooth_chooser_ptr_.rescan();
+  }
+
+  onEvent(chooserEvent) {
+    chooserEvent.type = MOJO_CHOOSER_EVENT_TYPE_MAP[chooserEvent.type];
+    this.events_.push(chooserEvent);
+    if (this.event_listener_ !== null) {
+      this.event_listener_();
+    }
+  }
+}
+
+async function initializeChromiumResources() {
+  content.mojom = await import(
+      '/gen/content/web_test/common/fake_bluetooth_chooser.mojom.m.js');
+  bluetooth.mojom = await import(
+      '/gen/device/bluetooth/public/mojom/test/fake_bluetooth.mojom.m.js');
+
+  const map = MOJO_CHOOSER_EVENT_TYPE_MAP;
+  const types = content.mojom.ChooserEventType;
+  map[types.CHOOSER_OPENED] = 'chooser-opened';
+  map[types.CHOOSER_CLOSED] = 'chooser-closed';
+  map[types.ADAPTER_REMOVED] = 'adapter-removed';
+  map[types.ADAPTER_DISABLED] = 'adapter-disabled';
+  map[types.ADAPTER_ENABLED] = 'adapter-enabled';
+  map[types.DISCOVERY_FAILED_TO_START] = 'discovery-failed-to-start';
+  map[types.DISCOVERING] = 'discovering';
+  map[types.DISCOVERY_IDLE] = 'discovery-idle';
+  map[types.ADD_OR_UPDATE_DEVICE] = 'add-or-update-device';
+
+  // If this line fails, it means that current environment does not support the
+  // Web Bluetooth Test API.
+  try {
+    navigator.bluetooth.test = new FakeBluetooth();
+  } catch {
+    throw 'Web Bluetooth Test API is not implemented on this ' +
+        'environment. See the bluetooth README at ' +
+        'https://github.com/web-platform-tests/wpt/blob/master/bluetooth/README.md#web-bluetooth-testing';
+  }
+}
diff --git a/testing/web-platform/tests/resources/chromium/web-bluetooth-test.js.headers b/testing/web-platform/tests/resources/chromium/web-bluetooth-test.js.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/web-bluetooth-test.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
diff --git a/testing/web-platform/tests/resources/chromium/webusb-child-test.js b/testing/web-platform/tests/resources/chromium/webusb-child-test.js
new file mode 100644
index 0000000000..21412f66b0
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webusb-child-test.js
@@ -0,0 +1,47 @@
+'use strict';
+
+// This polyfill prepares a child context to be attached to a parent context.
+// The parent must call navigator.usb.test.attachToContext() to attach to the
+// child context.
+(() => {
+  if (this.constructor.name === 'DedicatedWorkerGlobalScope' ||
+      this !== window.top) {
+
+    // Run Chromium specific set up code.
+    if (typeof MojoInterfaceInterceptor !== 'undefined') {
+      let messageChannel = new MessageChannel();
+      messageChannel.port1.onmessage = async (messageEvent) => {
+        if (messageEvent.data.type === 'Attach') {
+          messageEvent.data.interfaces.forEach(interfaceName => {
+            let interfaceInterceptor =
+                new MojoInterfaceInterceptor(interfaceName);
+            interfaceInterceptor.oninterfacerequest =
+              e => messageChannel.port1.postMessage({
+                type: interfaceName,
+                handle: e.handle
+              }, [e.handle]);
+            interfaceInterceptor.start();
+          });
+
+          // Wait for a call to GetDevices() to ensure that the interface
+          // handles are forwarded to the parent context.
+          try {
+            await navigator.usb.getDevices();
+          } catch (e) {
+            // This can happen in case of, for example, testing usb disallowed
+            // iframe.
+            console.error(`getDevices() throws error: ${e.name}: ${e.message}`);
+          }
+
+          messageChannel.port1.postMessage({ type: 'Complete' });
+        }
+      };
+
+      let message = { type: 'ReadyForAttachment', port: messageChannel.port2 };
+      if (typeof Window !== 'undefined')
+        parent.postMessage(message, '*', [messageChannel.port2]);
+      else
+        postMessage(message, [messageChannel.port2]);
+    }
+  }
+})();
diff --git a/testing/web-platform/tests/resources/chromium/webusb-child-test.js.headers b/testing/web-platform/tests/resources/chromium/webusb-child-test.js.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webusb-child-test.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
diff --git a/testing/web-platform/tests/resources/chromium/webusb-test.js b/testing/web-platform/tests/resources/chromium/webusb-test.js
new file mode 100644
index 0000000000..94ff1bcadd
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webusb-test.js
@@ -0,0 +1,582 @@
+'use strict';
+
+// This polyfill library implements the WebUSB Test API as specified here:
+// https://wicg.github.io/webusb/test/
+
+(() => {
+
+// These variables are logically members of the USBTest class but are defined
+// here to hide them from being visible as fields of navigator.usb.test.
+let internal = {
+  intialized: false,
+
+  webUsbService: null,
+  webUsbServiceInterceptor: null,
+
+  messagePort: null,
+};
+
+let mojom = {};
+
+async function loadMojomDefinitions() {
+  const deviceMojom =
+      await import('/gen/services/device/public/mojom/usb_device.mojom.m.js');
+  const serviceMojom = await import(
+      '/gen/third_party/blink/public/mojom/usb/web_usb_service.mojom.m.js');
+  return {
+    ...deviceMojom,
+    ...serviceMojom,
+  };
+}
+
+function getMessagePort(target) {
+  return new Promise(resolve => {
+    target.addEventListener('message', messageEvent => {
+      if (messageEvent.data.type === 'ReadyForAttachment') {
+        if (internal.messagePort === null) {
+          internal.messagePort = messageEvent.data.port;
+        }
+        resolve();
+      }
+    }, {once: true});
+  });
+}
+
+// Converts an ECMAScript String object to an instance of
+// mojo_base.mojom.String16.
+function mojoString16ToString(string16) {
+  return String.fromCharCode.apply(null, string16.data);
+}
+
+// Converts an instance of mojo_base.mojom.String16 to an ECMAScript String.
+function stringToMojoString16(string) {
+  let array = new Array(string.length);
+  for (var i = 0; i < string.length; ++i) {
+    array[i] = string.charCodeAt(i);
+  }
+  return { data: array }
+}
+
+function fakeDeviceInitToDeviceInfo(guid, init) {
+  let deviceInfo = {
+    guid: guid + "",
+    usbVersionMajor: init.usbVersionMajor,
+    usbVersionMinor: init.usbVersionMinor,
+    usbVersionSubminor: init.usbVersionSubminor,
+    classCode: init.deviceClass,
+    subclassCode: init.deviceSubclass,
+    protocolCode: init.deviceProtocol,
+    vendorId: init.vendorId,
+    productId: init.productId,
+    deviceVersionMajor: init.deviceVersionMajor,
+    deviceVersionMinor: init.deviceVersionMinor,
+    deviceVersionSubminor: init.deviceVersionSubminor,
+    manufacturerName: stringToMojoString16(init.manufacturerName),
+    productName: stringToMojoString16(init.productName),
+    serialNumber: stringToMojoString16(init.serialNumber),
+    activeConfiguration: init.activeConfigurationValue,
+    configurations: []
+  };
+  init.configurations.forEach(config => {
+    var configInfo = {
+      configurationValue: config.configurationValue,
+      configurationName: stringToMojoString16(config.configurationName),
+      selfPowered: false,
+      remoteWakeup: false,
+      maximumPower: 0,
+      interfaces: [],
+      extraData: new Uint8Array()
+    };
+    config.interfaces.forEach(iface => {
+      var interfaceInfo = {
+        interfaceNumber: iface.interfaceNumber,
+        alternates: []
+      };
+      iface.alternates.forEach(alternate => {
+        var alternateInfo = {
+          alternateSetting: alternate.alternateSetting,
+          classCode: alternate.interfaceClass,
+          subclassCode: alternate.interfaceSubclass,
+          protocolCode: alternate.interfaceProtocol,
+          interfaceName: stringToMojoString16(alternate.interfaceName),
+          endpoints: [],
+          extraData: new Uint8Array()
+        };
+        alternate.endpoints.forEach(endpoint => {
+          var endpointInfo = {
+            endpointNumber: endpoint.endpointNumber,
+            packetSize: endpoint.packetSize,
+            synchronizationType: mojom.UsbSynchronizationType.NONE,
+            usageType: mojom.UsbUsageType.DATA,
+            pollingInterval: 0,
+            extraData: new Uint8Array()
+          };
+          switch (endpoint.direction) {
+            case "in":
+              endpointInfo.direction = mojom.UsbTransferDirection.INBOUND;
+              break;
+            case "out":
+              endpointInfo.direction = mojom.UsbTransferDirection.OUTBOUND;
+              break;
+          }
+          switch (endpoint.type) {
+            case "bulk":
+              endpointInfo.type = mojom.UsbTransferType.BULK;
+              break;
+            case "interrupt":
+              endpointInfo.type = mojom.UsbTransferType.INTERRUPT;
+              break;
+            case "isochronous":
+              endpointInfo.type = mojom.UsbTransferType.ISOCHRONOUS;
+              break;
+          }
+          alternateInfo.endpoints.push(endpointInfo);
+        });
+        interfaceInfo.alternates.push(alternateInfo);
+      });
+      configInfo.interfaces.push(interfaceInfo);
+    });
+    deviceInfo.configurations.push(configInfo);
+  });
+  return deviceInfo;
+}
+
+function convertMojoDeviceFilters(input) {
+  let output = [];
+  input.forEach(filter => {
+    output.push(convertMojoDeviceFilter(filter));
+  });
+  return output;
+}
+
+function convertMojoDeviceFilter(input) {
+  let output = {};
+  if (input.hasVendorId)
+    output.vendorId = input.vendorId;
+  if (input.hasProductId)
+    output.productId = input.productId;
+  if (input.hasClassCode)
+    output.classCode = input.classCode;
+  if (input.hasSubclassCode)
+    output.subclassCode = input.subclassCode;
+  if (input.hasProtocolCode)
+    output.protocolCode = input.protocolCode;
+  if (input.serialNumber)
+    output.serialNumber = mojoString16ToString(input.serialNumber);
+  return output;
+}
+
+class FakeDevice {
+  constructor(deviceInit) {
+    this.info_ = deviceInit;
+    this.opened_ = false;
+    this.currentConfiguration_ = null;
+    this.claimedInterfaces_ = new Map();
+  }
+
+  getConfiguration() {
+    if (this.currentConfiguration_) {
+      return Promise.resolve({
+          value: this.currentConfiguration_.configurationValue });
+    } else {
+      return Promise.resolve({ value: 0 });
+    }
+  }
+
+  open() {
+    assert_false(this.opened_);
+    this.opened_ = true;
+    return Promise.resolve({result: {success: mojom.UsbOpenDeviceSuccess.OK}});
+  }
+
+  close() {
+    assert_true(this.opened_);
+    this.opened_ = false;
+    return Promise.resolve();
+  }
+
+  setConfiguration(value) {
+    assert_true(this.opened_);
+
+    let selectedConfiguration = this.info_.configurations.find(
+        configuration => configuration.configurationValue == value);
+    // Blink should never request an invalid configuration.
+    assert_not_equals(selectedConfiguration, undefined);
+    this.currentConfiguration_ = selectedConfiguration;
+    return Promise.resolve({ success: true });
+  }
+
+  async claimInterface(interfaceNumber) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    assert_false(this.claimedInterfaces_.has(interfaceNumber),
+                 'interface already claimed');
+
+    const protectedInterfaces = new Set([
+      mojom.USB_AUDIO_CLASS,
+      mojom.USB_HID_CLASS,
+      mojom.USB_MASS_STORAGE_CLASS,
+      mojom.USB_SMART_CARD_CLASS,
+      mojom.USB_VIDEO_CLASS,
+      mojom.USB_AUDIO_VIDEO_CLASS,
+      mojom.USB_WIRELESS_CLASS,
+    ]);
+
+    let iface = this.currentConfiguration_.interfaces.find(
+        iface => iface.interfaceNumber == interfaceNumber);
+    // Blink should never request an invalid interface or alternate.
+    assert_false(iface == undefined);
+    if (iface.alternates.some(
+            alt => protectedInterfaces.has(alt.interfaceClass))) {
+      return {result: mojom.UsbClaimInterfaceResult.kProtectedClass};
+    }
+
+    this.claimedInterfaces_.set(interfaceNumber, 0);
+    return {result: mojom.UsbClaimInterfaceResult.kSuccess};
+  }
+
+  releaseInterface(interfaceNumber) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    assert_true(this.claimedInterfaces_.has(interfaceNumber));
+    this.claimedInterfaces_.delete(interfaceNumber);
+    return Promise.resolve({ success: true });
+  }
+
+  setInterfaceAlternateSetting(interfaceNumber, alternateSetting) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    assert_true(this.claimedInterfaces_.has(interfaceNumber));
+
+    let iface = this.currentConfiguration_.interfaces.find(
+        iface => iface.interfaceNumber == interfaceNumber);
+    // Blink should never request an invalid interface or alternate.
+    assert_false(iface == undefined);
+    assert_true(iface.alternates.some(
+        x => x.alternateSetting == alternateSetting));
+    this.claimedInterfaces_.set(interfaceNumber, alternateSetting);
+    return Promise.resolve({ success: true });
+  }
+
+  reset() {
+    assert_true(this.opened_);
+    return Promise.resolve({ success: true });
+  }
+
+  clearHalt(endpoint) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    // TODO(reillyg): Assert that endpoint is valid.
+    return Promise.resolve({ success: true });
+  }
+
+  async controlTransferIn(params, length, timeout) {
+    assert_true(this.opened_);
+
+    if ((params.recipient == mojom.UsbControlTransferRecipient.INTERFACE ||
+         params.recipient == mojom.UsbControlTransferRecipient.ENDPOINT) &&
+        this.currentConfiguration_ == null) {
+      return {
+        status: mojom.UsbTransferStatus.PERMISSION_DENIED,
+      };
+    }
+
+    return {
+      status: mojom.UsbTransferStatus.OK,
+      data: {
+        buffer: [
+          length >> 8, length & 0xff, params.request, params.value >> 8,
+          params.value & 0xff, params.index >> 8, params.index & 0xff
+        ]
+      }
+    };
+  }
+
+  async controlTransferOut(params, data, timeout) {
+    assert_true(this.opened_);
+
+    if ((params.recipient == mojom.UsbControlTransferRecipient.INTERFACE ||
+         params.recipient == mojom.UsbControlTransferRecipient.ENDPOINT) &&
+        this.currentConfiguration_ == null) {
+      return {
+        status: mojom.UsbTransferStatus.PERMISSION_DENIED,
+      };
+    }
+
+    return {status: mojom.UsbTransferStatus.OK, bytesWritten: data.byteLength};
+  }
+
+  genericTransferIn(endpointNumber, length, timeout) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    // TODO(reillyg): Assert that endpoint is valid.
+    let data = new Array(length);
+    for (let i = 0; i < length; ++i)
+      data[i] = i & 0xff;
+    return Promise.resolve(
+        {status: mojom.UsbTransferStatus.OK, data: {buffer: data}});
+  }
+
+  genericTransferOut(endpointNumber, data, timeout) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    // TODO(reillyg): Assert that endpoint is valid.
+    return Promise.resolve(
+        {status: mojom.UsbTransferStatus.OK, bytesWritten: data.byteLength});
+  }
+
+  isochronousTransferIn(endpointNumber, packetLengths, timeout) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    // TODO(reillyg): Assert that endpoint is valid.
+    let data = new Array(packetLengths.reduce((a, b) => a + b, 0));
+    let dataOffset = 0;
+    let packets = new Array(packetLengths.length);
+    for (let i = 0; i < packetLengths.length; ++i) {
+      for (let j = 0; j < packetLengths[i]; ++j)
+        data[dataOffset++] = j & 0xff;
+      packets[i] = {
+        length: packetLengths[i],
+        transferredLength: packetLengths[i],
+        status: mojom.UsbTransferStatus.OK
+      };
+    }
+    return Promise.resolve({data: {buffer: data}, packets: packets});
+  }
+
+  isochronousTransferOut(endpointNumber, data, packetLengths, timeout) {
+    assert_true(this.opened_);
+    assert_false(this.currentConfiguration_ == null, 'device configured');
+    // TODO(reillyg): Assert that endpoint is valid.
+    let packets = new Array(packetLengths.length);
+    for (let i = 0; i < packetLengths.length; ++i) {
+      packets[i] = {
+        length: packetLengths[i],
+        transferredLength: packetLengths[i],
+        status: mojom.UsbTransferStatus.OK
+      };
+    }
+    return Promise.resolve({ packets: packets });
+  }
+}
+
+class FakeWebUsbService {
+  constructor() {
+    this.receiver_ = new mojom.WebUsbServiceReceiver(this);
+    this.devices_ = new Map();
+    this.devicesByGuid_ = new Map();
+    this.client_ = null;
+    this.nextGuid_ = 0;
+  }
+
+  addBinding(handle) {
+    this.receiver_.$.bindHandle(handle);
+  }
+
+  addDevice(fakeDevice, info) {
+    let device = {
+      fakeDevice: fakeDevice,
+      guid: (this.nextGuid_++).toString(),
+      info: info,
+      receivers: [],
+    };
+    this.devices_.set(fakeDevice, device);
+    this.devicesByGuid_.set(device.guid, device);
+    if (this.client_)
+      this.client_.onDeviceAdded(fakeDeviceInitToDeviceInfo(device.guid, info));
+  }
+
+  async forgetDevice(guid) {
+    // Permissions are currently untestable through WPT.
+  }
+
+  removeDevice(fakeDevice) {
+    let device = this.devices_.get(fakeDevice);
+    if (!device)
+      throw new Error('Cannot remove unknown device.');
+
+    for (const receiver of device.receivers)
+      receiver.$.close();
+    this.devices_.delete(device.fakeDevice);
+    this.devicesByGuid_.delete(device.guid);
+    if (this.client_) {
+      this.client_.onDeviceRemoved(
+          fakeDeviceInitToDeviceInfo(device.guid, device.info));
+    }
+  }
+
+  removeAllDevices() {
+    this.devices_.forEach(device => {
+      for (const receiver of device.receivers)
+        receiver.$.close();
+      this.client_.onDeviceRemoved(
+          fakeDeviceInitToDeviceInfo(device.guid, device.info));
+    });
+    this.devices_.clear();
+    this.devicesByGuid_.clear();
+  }
+
+  getDevices() {
+    let devices = [];
+    this.devices_.forEach(device => {
+      devices.push(fakeDeviceInitToDeviceInfo(device.guid, device.info));
+    });
+    return Promise.resolve({ results: devices });
+  }
+
+  getDevice(guid, request) {
+    let retrievedDevice = this.devicesByGuid_.get(guid);
+    if (retrievedDevice) {
+      const receiver =
+          new mojom.UsbDeviceReceiver(new FakeDevice(retrievedDevice.info));
+      receiver.$.bindHandle(request.handle);
+      receiver.onConnectionError.addListener(() => {
+        if (retrievedDevice.fakeDevice.onclose)
+          retrievedDevice.fakeDevice.onclose();
+      });
+      retrievedDevice.receivers.push(receiver);
+    } else {
+      request.handle.close();
+    }
+  }
+
+  getPermission(deviceFilters) {
+    return new Promise(resolve => {
+      if (navigator.usb.test.onrequestdevice) {
+        navigator.usb.test.onrequestdevice(
+            new USBDeviceRequestEvent(deviceFilters, resolve));
+      } else {
+        resolve({ result: null });
+      }
+    });
+  }
+
+  setClient(client) {
+    this.client_ = client;
+  }
+}
+
+class USBDeviceRequestEvent {
+  constructor(deviceFilters, resolve) {
+    this.filters = convertMojoDeviceFilters(deviceFilters);
+    this.resolveFunc_ = resolve;
+  }
+
+  respondWith(value) {
+    // Wait until |value| resolves (if it is a Promise). This function returns
+    // no value.
+    Promise.resolve(value).then(fakeDevice => {
+      let device = internal.webUsbService.devices_.get(fakeDevice);
+      let result = null;
+      if (device) {
+        result = fakeDeviceInitToDeviceInfo(device.guid, device.info);
+      }
+      this.resolveFunc_({ result: result });
+    }, () => {
+      this.resolveFunc_({ result: null });
+    });
+  }
+}
+
+// Unlike FakeDevice this class is exported to callers of USBTest.addFakeDevice.
+class FakeUSBDevice {
+  constructor() {
+    this.onclose = null;
+  }
+
+  disconnect() {
+    setTimeout(() => internal.webUsbService.removeDevice(this), 0);
+  }
+}
+
+class USBTest {
+  constructor() {
+    this.onrequestdevice = undefined;
+  }
+
+  async initialize() {
+    if (internal.initialized)
+      return;
+
+    // Be ready to handle 'ReadyForAttachment' message from child iframes.
+    if ('window' in self) {
+      getMessagePort(window);
+    }
+
+    mojom = await loadMojomDefinitions();
+    internal.webUsbService = new FakeWebUsbService();
+    internal.webUsbServiceInterceptor =
+        new MojoInterfaceInterceptor(mojom.WebUsbService.$interfaceName);
+    internal.webUsbServiceInterceptor.oninterfacerequest =
+        e => internal.webUsbService.addBinding(e.handle);
+    internal.webUsbServiceInterceptor.start();
+
+    // Wait for a call to GetDevices() to pass between the renderer and the
+    // mock in order to establish that everything is set up.
+    await navigator.usb.getDevices();
+    internal.initialized = true;
+  }
+
+  // Returns a promise that is resolved when the implementation of |usb| in the
+  // global scope for |context| is controlled by the current context.
+  attachToContext(context) {
+    if (!internal.initialized)
+      throw new Error('Call initialize() before attachToContext()');
+
+    let target = context.constructor.name === 'Worker' ? context : window;
+    return getMessagePort(target).then(() => {
+      return new Promise(resolve => {
+        internal.messagePort.onmessage = channelEvent => {
+          switch (channelEvent.data.type) {
+            case mojom.WebUsbService.$interfaceName:
+              internal.webUsbService.addBinding(channelEvent.data.handle);
+              break;
+            case 'Complete':
+              resolve();
+              break;
+          }
+        };
+        internal.messagePort.postMessage({
+          type: 'Attach',
+          interfaces: [
+            mojom.WebUsbService.$interfaceName,
+          ]
+        });
+      });
+    });
+  }
+
+  addFakeDevice(deviceInit) {
+    if (!internal.initialized)
+      throw new Error('Call initialize() before addFakeDevice().');
+
+    // |addDevice| and |removeDevice| are called in a setTimeout callback so
+    // that tests do not rely on the device being immediately available which
+    // may not be true for all implementations of this test API.
+    let fakeDevice = new FakeUSBDevice();
+    setTimeout(
+        () => internal.webUsbService.addDevice(fakeDevice, deviceInit), 0);
+    return fakeDevice;
+  }
+
+  reset() {
+    if (!internal.initialized)
+      throw new Error('Call initialize() before reset().');
+
+    // Reset the mocks in a setTimeout callback so that tests do not rely on
+    // the fact that this polyfill can do this synchronously.
+    return new Promise(resolve => {
+      setTimeout(() => {
+        if (internal.messagePort !== null)
+          internal.messagePort.close();
+        internal.messagePort = null;
+        internal.webUsbService.removeAllDevices();
+        resolve();
+      }, 0);
+    });
+  }
+}
+
+navigator.usb.test = new USBTest();
+
+})();
diff --git a/testing/web-platform/tests/resources/chromium/webusb-test.js.headers b/testing/web-platform/tests/resources/chromium/webusb-test.js.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webusb-test.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
diff --git a/testing/web-platform/tests/resources/chromium/webxr-test-math-helper.js b/testing/web-platform/tests/resources/chromium/webxr-test-math-helper.js
new file mode 100644
index 0000000000..22c6c12d08
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webxr-test-math-helper.js
@@ -0,0 +1,298 @@
+'use strict';
+
+// Math helper - used mainly in hit test implementation done by webxr-test.js
+class XRMathHelper {
+  static toString(p) {
+    return "[" + p.x + "," + p.y + "," + p.z + "," + p.w + "]";
+  }
+
+  static transform_by_matrix(matrix, point) {
+    return {
+      x : matrix[0] * point.x + matrix[4] * point.y + matrix[8] * point.z + matrix[12] * point.w,
+      y : matrix[1] * point.x + matrix[5] * point.y + matrix[9] * point.z + matrix[13] * point.w,
+      z : matrix[2] * point.x + matrix[6] * point.y + matrix[10] * point.z + matrix[14] * point.w,
+      w : matrix[3] * point.x + matrix[7] * point.y + matrix[11] * point.z + matrix[15] * point.w,
+    };
+  }
+
+  static neg(p) {
+    return {x : -p.x, y : -p.y, z : -p.z, w : p.w};
+  }
+
+  static sub(lhs, rhs) {
+    // .w is treated here like an entity type, 1 signifies points, 0 signifies vectors.
+    // point - point, point - vector, vector - vector are ok, vector - point is not.
+    if (lhs.w != rhs.w && lhs.w == 0.0) {
+      throw new Error("vector - point not allowed: " + toString(lhs) + "-" + toString(rhs));
+    }
+
+    return {x : lhs.x - rhs.x, y : lhs.y - rhs.y, z : lhs.z - rhs.z, w : lhs.w - rhs.w};
+  }
+
+  static add(lhs, rhs) {
+    if (lhs.w == rhs.w && lhs.w == 1.0) {
+      throw new Error("point + point not allowed", p1, p2);
+    }
+
+    return {x : lhs.x + rhs.x, y : lhs.y + rhs.y, z : lhs.z + rhs.z, w : lhs.w + rhs.w};
+  }
+
+  static cross(lhs, rhs) {
+    if (lhs.w != 0.0 || rhs.w != 0.0) {
+      throw new Error("cross product not allowed: " + toString(lhs) + "x" + toString(rhs));
+    }
+
+    return {
+      x : lhs.y * rhs.z - lhs.z * rhs.y,
+      y : lhs.z * rhs.x - lhs.x * rhs.z,
+      z : lhs.x * rhs.y - lhs.y * rhs.x,
+      w : 0
+    };
+  }
+
+  static dot(lhs, rhs) {
+    if (lhs.w != 0 || rhs.w != 0) {
+      throw new Error("dot product not allowed: " + toString(lhs) + "x" + toString(rhs));
+    }
+
+    return lhs.x * rhs.x + lhs.y * rhs.y + lhs.z * rhs.z;
+  }
+
+  static mul(scalar, vector) {
+    if (vector.w != 0) {
+      throw new Error("scalar * vector not allowed", scalar, vector);
+    }
+
+    return {x : vector.x * scalar, y : vector.y * scalar, z : vector.z * scalar, w : vector.w};
+  }
+
+  static length(vector) {
+    return Math.sqrt(XRMathHelper.dot(vector, vector));
+  }
+
+  static normalize(vector) {
+    const l = XRMathHelper.length(vector);
+    return XRMathHelper.mul(1.0/l, vector);
+  }
+
+  // All |face|'s points and |point| must be co-planar.
+  static pointInFace(point, face) {
+    const normalize = XRMathHelper.normalize;
+    const sub = XRMathHelper.sub;
+    const length = XRMathHelper.length;
+    const cross = XRMathHelper.cross;
+
+    let onTheRight = null;
+    let previous_point = face[face.length - 1];
+
+    // |point| is in |face| if it's on the same side of all the edges.
+    for (let i = 0; i < face.length; ++i) {
+      const current_point = face[i];
+
+      const edge_direction = normalize(sub(current_point, previous_point));
+      const turn_direction = normalize(sub(point, current_point));
+
+      const sin_turn_angle = length(cross(edge_direction, turn_direction));
+
+      if (onTheRight == null) {
+        onTheRight = sin_turn_angle >= 0;
+      } else {
+        if (onTheRight && sin_turn_angle < 0) return false;
+        if (!onTheRight && sin_turn_angle > 0) return false;
+      }
+
+      previous_point = current_point;
+    }
+
+    return true;
+  }
+
+  static det2x2(m00, m01, m10, m11) {
+    return m00 * m11 - m01 * m10;
+  }
+
+  static det3x3(
+    m00, m01, m02,
+    m10, m11, m12,
+    m20, m21, m22
+  ){
+    const det2x2 = XRMathHelper.det2x2;
+
+    return    m00 * det2x2(m11, m12, m21, m22)
+            - m01 * det2x2(m10, m12, m20, m22)
+            + m02 * det2x2(m10, m11, m20, m21);
+  }
+
+  static det4x4(
+    m00, m01, m02, m03,
+    m10, m11, m12, m13,
+    m20, m21, m22, m23,
+    m30, m31, m32, m33
+  ) {
+    const det3x3 = XRMathHelper.det3x3;
+
+    return  m00 * det3x3(m11, m12, m13,
+                         m21, m22, m23,
+                         m31, m32, m33)
+          - m01 * det3x3(m10, m12, m13,
+                         m20, m22, m23,
+                         m30, m32, m33)
+          + m02 * det3x3(m10, m11, m13,
+                         m20, m21, m23,
+                         m30, m31, m33)
+          - m03 * det3x3(m10, m11, m12,
+                         m20, m21, m22,
+                         m30, m31, m32);
+  }
+
+  static inv2(m) {
+    // mij - i-th column, j-th row
+    const m00 = m[0],  m01 = m[1],  m02 = m[2],  m03 = m[3];
+    const m10 = m[4],  m11 = m[5],  m12 = m[6],  m13 = m[7];
+    const m20 = m[8],  m21 = m[9],  m22 = m[10], m23 = m[11];
+    const m30 = m[12], m31 = m[13], m32 = m[14], m33 = m[15];
+
+    const det = det4x4(
+      m00, m01, m02, m03,
+      m10, m11, m12, m13,
+      m20, m21, m22, m23,
+      m30, m31, m32, m33
+    );
+  }
+
+  static transpose(m) {
+    const result = Array(16);
+    for (let i = 0; i < 4; i++) {
+      for (let j = 0; j < 4; j++) {
+        result[i * 4 + j] = m[j * 4 + i];
+      }
+    }
+    return result;
+  }
+
+  // Inverts the matrix, ported from transformation_matrix.cc.
+  static inverse(m) {
+    const det3x3 = XRMathHelper.det3x3;
+
+    // mij - i-th column, j-th row
+    const m00 = m[0],  m01 = m[1],  m02 = m[2],  m03 = m[3];
+    const m10 = m[4],  m11 = m[5],  m12 = m[6],  m13 = m[7];
+    const m20 = m[8],  m21 = m[9],  m22 = m[10], m23 = m[11];
+    const m30 = m[12], m31 = m[13], m32 = m[14], m33 = m[15];
+
+    const det = XRMathHelper.det4x4(
+      m00, m01, m02, m03,
+      m10, m11, m12, m13,
+      m20, m21, m22, m23,
+      m30, m31, m32, m33
+    );
+
+    if (Math.abs(det) < 0.0001) {
+      return null;
+    }
+
+    const invDet = 1.0 / det;
+    // Calculate `comatrix * 1/det`:
+    const result2 = [
+      // First column (m0r):
+      invDet * det3x3(m11, m12, m13, m21, m22, m23, m32, m32, m33),
+      -invDet * det3x3(m10, m12, m13, m20, m22, m23, m30, m32, m33),
+      invDet * det3x3(m10, m11, m13, m20, m21, m23, m30, m31, m33),
+      -invDet * det3x3(m10, m11, m12, m20, m21, m22, m30, m31, m32),
+      // Second column (m1r):
+      -invDet * det3x3(m01, m02, m03, m21, m22, m23, m32, m32, m33),
+      invDet * det3x3(m00, m02, m03, m20, m22, m23, m30, m32, m33),
+      -invDet * det3x3(m00, m01, m03, m20, m21, m23, m30, m31, m33),
+      invDet * det3x3(m00, m01, m02, m20, m21, m22, m30, m31, m32),
+      // Third column (m2r):
+      invDet * det3x3(m01, m02, m03, m11, m12, m13, m31, m32, m33),
+      -invDet * det3x3(m00, m02, m03, m10, m12, m13, m30, m32, m33),
+      invDet * det3x3(m00, m01, m03, m10, m11, m13, m30, m31, m33),
+      -invDet * det3x3(m00, m01, m02, m10, m11, m12, m30, m31, m32),
+      // Fourth column (m3r):
+      -invDet * det3x3(m01, m02, m03, m11, m12, m13, m21, m22, m23),
+      invDet * det3x3(m00, m02, m03, m10, m12, m13, m20, m22, m23),
+      -invDet * det3x3(m00, m01, m03, m10, m11, m13, m20, m21, m23),
+      invDet * det3x3(m00, m01, m02, m10, m11, m12, m20, m21, m22),
+    ];
+
+    // Actual inverse is `1/det * transposed(comatrix)`:
+    return XRMathHelper.transpose(result2);
+  }
+
+  static mul4x4(m1, m2) {
+    if (m1 == null || m2 == null) {
+      return null;
+    }
+
+    const result = Array(16);
+
+    for (let row = 0; row < 4; row++) {
+      for (let col = 0; col < 4; col++) {
+        result[4 * col + row] = 0;
+        for(let i = 0; i < 4; i++) {
+          result[4 * col + row] += m1[4 * i + row] * m2[4 * col + i];
+        }
+      }
+    }
+
+    return result;
+  }
+
+  // Decomposes a matrix, with the assumption that the passed in matrix is
+  // a rigid transformation (i.e. position and rotation *only*!).
+  // The result is an object with `position` and `orientation` keys, which should
+  // be compatible with FakeXRRigidTransformInit.
+  // The implementation should match the behavior of gfx::Transform, but assumes
+  // that scale, skew & perspective are not present in the matrix so it could be
+  // simplified.
+  static decomposeRigidTransform(m) {
+    const m00 = m[0],  m01 = m[1],  m02 = m[2],  m03 = m[3];
+    const m10 = m[4],  m11 = m[5],  m12 = m[6],  m13 = m[7];
+    const m20 = m[8],  m21 = m[9],  m22 = m[10], m23 = m[11];
+    const m30 = m[12], m31 = m[13], m32 = m[14], m33 = m[15];
+
+    const position = [m30, m31, m32];
+    const orientation = [0, 0, 0, 0];
+
+    const trace = m00 + m11 + m22;
+    if (trace > 0) {
+      const S = Math.sqrt(trace + 1) * 2;
+      orientation[3] = 0.25 * S;
+      orientation[0] = (m12 - m21) / S;
+      orientation[1] = (m20 - m02) / S;
+      orientation[2] = (m01 - m10) / S;
+    } else if (m00 > m11 && m00 > m22) {
+      const S = Math.sqrt(1.0 + m00 - m11 - m22) * 2;
+      orientation[3] = (m12 - m21) / S;
+      orientation[0] = 0.25 * S;
+      orientation[1] = (m01 + m10) / S;
+      orientation[2] = (m20 + m02) / S;
+    } else if (m11 > m22) {
+      const S = Math.sqrt(1.0 + m11 - m00 - m22) * 2;
+      orientation[3] = (m20 - m02) / S;
+      orientation[0] = (m01 + m10) / S;
+      orientation[1] = 0.25 * S;
+      orientation[2] = (m12 + m21) / S;
+    } else {
+      const S = Math.sqrt(1.0 + m22 - m00 - m11) * 2;
+      orientation[3] = (m01 - m10) / S;
+      orientation[0] = (m20 + m02) / S;
+      orientation[1] = (m12 + m21) / S;
+      orientation[2] = 0.25 * S;
+    }
+
+    return { position, orientation };
+  }
+
+  static identity() {
+    return [
+      1, 0, 0, 0,
+      0, 1, 0, 0,
+      0, 0, 1, 0,
+      0, 0, 0, 1
+    ];
+  };
+}
+
+XRMathHelper.EPSILON = 0.001;
diff --git a/testing/web-platform/tests/resources/chromium/webxr-test-math-helper.js.headers b/testing/web-platform/tests/resources/chromium/webxr-test-math-helper.js.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webxr-test-math-helper.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8
diff --git a/testing/web-platform/tests/resources/chromium/webxr-test.js b/testing/web-platform/tests/resources/chromium/webxr-test.js
new file mode 100644
index 0000000000..ab2c6faa0e
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webxr-test.js
@@ -0,0 +1,2128 @@
+import * as vrMojom from '/gen/device/vr/public/mojom/vr_service.mojom.m.js';
+import * as xrSessionMojom from '/gen/device/vr/public/mojom/xr_session.mojom.m.js';
+import {GamepadHand, GamepadMapping} from '/gen/device/gamepad/public/mojom/gamepad.mojom.m.js';
+
+// This polyfill library implements the WebXR Test API as specified here:
+// https://github.com/immersive-web/webxr-test-api
+
+const defaultMojoFromFloor = {
+  matrix: [1, 0,     0, 0,
+           0, 1,     0, 0,
+           0, 0,     1, 0,
+           0, -1.65, 0, 1]
+};
+const default_stage_parameters = {
+  mojoFromFloor: defaultMojoFromFloor,
+  bounds: null
+};
+
+const default_framebuffer_scale = 0.7;
+
+function getMatrixFromTransform(transform) {
+  const x = transform.orientation[0];
+  const y = transform.orientation[1];
+  const z = transform.orientation[2];
+  const w = transform.orientation[3];
+
+  const m11 = 1.0 - 2.0 * (y * y + z * z);
+  const m21 = 2.0 * (x * y + z * w);
+  const m31 = 2.0 * (x * z - y * w);
+
+  const m12 = 2.0 * (x * y - z * w);
+  const m22 = 1.0 - 2.0 * (x * x + z * z);
+  const m32 = 2.0 * (y * z + x * w);
+
+  const m13 = 2.0 * (x * z + y * w);
+  const m23 = 2.0 * (y * z - x * w);
+  const m33 = 1.0 - 2.0 * (x * x + y * y);
+
+  const m14 = transform.position[0];
+  const m24 = transform.position[1];
+  const m34 = transform.position[2];
+
+  // Column-major linearized order is expected.
+  return [m11, m21, m31, 0,
+          m12, m22, m32, 0,
+          m13, m23, m33, 0,
+          m14, m24, m34, 1];
+}
+
+function getPoseFromTransform(transform) {
+  const [px, py, pz] = transform.position;
+  const [ox, oy, oz, ow] = transform.orientation;
+  return {
+    position: {x: px, y: py, z: pz},
+    orientation: {x: ox, y: oy, z: oz, w: ow},
+  };
+}
+
+function composeGFXTransform(fakeTransformInit) {
+  return {matrix: getMatrixFromTransform(fakeTransformInit)};
+}
+
+// Value equality for camera image init objects - they must contain `width` &
+// `height` properties and may contain `pixels` property.
+function isSameCameraImageInit(rhs, lhs) {
+  return lhs.width === rhs.width && lhs.height === rhs.height && lhs.pixels === rhs.pixels;
+}
+
+class ChromeXRTest {
+  constructor() {
+    this.mockVRService_ = new MockVRService();
+  }
+
+  // WebXR Test API
+  simulateDeviceConnection(init_params) {
+    return Promise.resolve(this.mockVRService_._addRuntime(init_params));
+  }
+
+  disconnectAllDevices() {
+    this.mockVRService_._removeAllRuntimes();
+    return Promise.resolve();
+  }
+
+  simulateUserActivation(callback) {
+    if (window.top !== window) {
+      // test_driver.click only works for the toplevel frame. This alternate
+      // Chrome-specific method is sufficient for starting an XR session in an
+      // iframe, and is used in platform-specific tests.
+      //
+      // TODO(https://github.com/web-platform-tests/wpt/issues/20282): use
+      // a cross-platform method if available.
+      xr_debug('simulateUserActivation', 'use eventSender');
+      document.addEventListener('click', callback);
+      eventSender.mouseMoveTo(0, 0);
+      eventSender.mouseDown();
+      eventSender.mouseUp();
+      document.removeEventListener('click', callback);
+      return;
+    }
+    const button = document.createElement('button');
+    button.textContent = 'click to continue test';
+    button.style.display = 'block';
+    button.style.fontSize = '20px';
+    button.style.padding = '10px';
+    button.onclick = () => {
+      callback();
+      document.body.removeChild(button);
+    };
+    document.body.appendChild(button);
+    test_driver.click(button);
+  }
+
+  // Helper method leveraged by chrome-specific setups.
+  Debug(name, msg) {
+    console.log(new Date().toISOString() + ' DEBUG[' + name + '] ' + msg);
+  }
+}
+
+// Mocking class definitions
+
+// Mock service implements the VRService mojo interface.
+class MockVRService {
+  constructor() {
+    this.receiver_ = new vrMojom.VRServiceReceiver(this);
+    this.runtimes_ = [];
+
+    this.interceptor_ =
+        new MojoInterfaceInterceptor(vrMojom.VRService.$interfaceName);
+    this.interceptor_.oninterfacerequest =
+        e => this.receiver_.$.bindHandle(e.handle);
+    this.interceptor_.start();
+  }
+
+  // WebXR Test API Implementation Helpers
+  _addRuntime(fakeDeviceInit) {
+    const runtime = new MockRuntime(fakeDeviceInit, this);
+    this.runtimes_.push(runtime);
+
+    if (this.client_) {
+      this.client_.onDeviceChanged();
+    }
+
+    return runtime;
+  }
+
+  _removeAllRuntimes() {
+    if (this.client_) {
+      this.client_.onDeviceChanged();
+    }
+
+    this.runtimes_ = [];
+  }
+
+  _removeRuntime(device) {
+    const index = this.runtimes_.indexOf(device);
+    if (index >= 0) {
+      this.runtimes_.splice(index, 1);
+      if (this.client_) {
+        this.client_.onDeviceChanged();
+      }
+    }
+  }
+
+  // VRService overrides
+  setClient(client) {
+    if (this.client_) {
+      throw new Error("setClient should only be called once");
+    }
+
+    this.client_ = client;
+  }
+
+  requestSession(sessionOptions) {
+    const requests = [];
+    // Request a session from all the runtimes.
+    for (let i = 0; i < this.runtimes_.length; i++) {
+      requests[i] = this.runtimes_[i]._requestRuntimeSession(sessionOptions);
+    }
+
+    return Promise.all(requests).then((results) => {
+      // Find and return the first successful result.
+      for (let i = 0; i < results.length; i++) {
+        if (results[i].session) {
+          // Construct a dummy metrics recorder
+          const metricsRecorderPtr = new vrMojom.XRSessionMetricsRecorderRemote();
+          metricsRecorderPtr.$.bindNewPipeAndPassReceiver().handle.close();
+
+          const success = {
+            session: results[i].session,
+            metricsRecorder: metricsRecorderPtr,
+          };
+
+          return {result: {success}};
+        }
+      }
+
+      // If there were no successful results, returns a null session.
+      return {
+        result: {failureReason: vrMojom.RequestSessionError.NO_RUNTIME_FOUND}
+      };
+    });
+  }
+
+  supportsSession(sessionOptions) {
+    const requests = [];
+    // Check supports on all the runtimes.
+    for (let i = 0; i < this.runtimes_.length; i++) {
+      requests[i] = this.runtimes_[i]._runtimeSupportsSession(sessionOptions);
+    }
+
+    return Promise.all(requests).then((results) => {
+      // Find and return the first successful result.
+      for (let i = 0; i < results.length; i++) {
+        if (results[i].supportsSession) {
+          return results[i];
+        }
+      }
+
+      // If there were no successful results, returns false.
+      return {supportsSession: false};
+    });
+  }
+
+  exitPresent() {
+    return Promise.resolve();
+  }
+
+  setFramesThrottled(throttled) {
+    this.setFramesThrottledImpl(throttled);
+  }
+
+  // We cannot override the mojom interceptors via the prototype; so this method
+  // and the above indirection exist to allow overrides by internal code.
+  setFramesThrottledImpl(throttled) {}
+
+  // Only handles asynchronous calls to makeXrCompatible. Synchronous calls are
+  // not supported in Javascript.
+  makeXrCompatible() {
+    if (this.runtimes_.length == 0) {
+      return {
+        xrCompatibleResult: vrMojom.XrCompatibleResult.kNoDeviceAvailable
+      };
+    }
+    return {xrCompatibleResult: vrMojom.XrCompatibleResult.kAlreadyCompatible};
+  }
+}
+
+class FakeXRAnchorController {
+  constructor() {
+    // Private properties.
+    this.device_ = null;
+    this.id_ = null;
+    this.dirty_ = true;
+
+    // Properties backing up public attributes / methods.
+    this.deleted_ = false;
+    this.paused_ = false;
+    this.anchorOrigin_ = XRMathHelper.identity();
+  }
+
+  // WebXR Test API (Anchors Extension)
+  get deleted() {
+    return this.deleted_;
+  }
+
+  pauseTracking() {
+    if(!this.paused_) {
+      this.paused_ = true;
+      this.dirty_ = true;
+    }
+  }
+
+  resumeTracking() {
+    if(this.paused_) {
+      this.paused_ = false;
+      this.dirty_ = true;
+    }
+  }
+
+  stopTracking() {
+    if(!this.deleted_) {
+      this.device_._deleteAnchorController(this.id_);
+
+      this.deleted_ = true;
+      this.dirty_ = true;
+    }
+  }
+
+  setAnchorOrigin(anchorOrigin) {
+    this.anchorOrigin_ = getMatrixFromTransform(anchorOrigin);
+    this.dirty_ = true;
+  }
+
+  // Internal implementation:
+  set id(value) {
+    this.id_ = value;
+  }
+
+  set device(value) {
+    this.device_ = value;
+  }
+
+  get dirty() {
+    return this.dirty_;
+  }
+
+  get paused() {
+    return this.paused_;
+  }
+
+  _markProcessed() {
+    this.dirty_ = false;
+  }
+
+  _getAnchorOrigin() {
+    return this.anchorOrigin_;
+  }
+}
+
+// Implements XRFrameDataProvider and XRPresentationProvider. Maintains a mock
+// for XRPresentationProvider. Implements FakeXRDevice test API.
+class MockRuntime {
+  // Mapping from string feature names to the corresponding mojo types.
+  // This is exposed as a member for extensibility.
+  static _featureToMojoMap = {
+    'viewer': xrSessionMojom.XRSessionFeature.REF_SPACE_VIEWER,
+    'local': xrSessionMojom.XRSessionFeature.REF_SPACE_LOCAL,
+    'local-floor': xrSessionMojom.XRSessionFeature.REF_SPACE_LOCAL_FLOOR,
+    'bounded-floor': xrSessionMojom.XRSessionFeature.REF_SPACE_BOUNDED_FLOOR,
+    'unbounded': xrSessionMojom.XRSessionFeature.REF_SPACE_UNBOUNDED,
+    'hit-test': xrSessionMojom.XRSessionFeature.HIT_TEST,
+    'dom-overlay': xrSessionMojom.XRSessionFeature.DOM_OVERLAY,
+    'light-estimation': xrSessionMojom.XRSessionFeature.LIGHT_ESTIMATION,
+    'anchors': xrSessionMojom.XRSessionFeature.ANCHORS,
+    'depth-sensing': xrSessionMojom.XRSessionFeature.DEPTH,
+    'secondary-views': xrSessionMojom.XRSessionFeature.SECONDARY_VIEWS,
+    'camera-access': xrSessionMojom.XRSessionFeature.CAMERA_ACCESS,
+    'layers': xrSessionMojom.XRSessionFeature.LAYERS,
+  };
+
+  static _sessionModeToMojoMap = {
+    "inline": xrSessionMojom.XRSessionMode.kInline,
+    "immersive-vr": xrSessionMojom.XRSessionMode.kImmersiveVr,
+    "immersive-ar": xrSessionMojom.XRSessionMode.kImmersiveAr,
+  };
+
+  static _environmentBlendModeToMojoMap = {
+    "opaque": vrMojom.XREnvironmentBlendMode.kOpaque,
+    "alpha-blend": vrMojom.XREnvironmentBlendMode.kAlphaBlend,
+    "additive": vrMojom.XREnvironmentBlendMode.kAdditive,
+  };
+
+  static _interactionModeToMojoMap = {
+    "screen-space": vrMojom.XRInteractionMode.kScreenSpace,
+    "world-space": vrMojom.XRInteractionMode.kWorldSpace,
+  };
+
+  constructor(fakeDeviceInit, service) {
+    this.sessionClient_ = null;
+    this.presentation_provider_ = new MockXRPresentationProvider();
+
+    this.pose_ = null;
+    this.next_frame_id_ = 0;
+    this.bounds_ = null;
+    this.send_mojo_space_reset_ = false;
+    this.stageParameters_ = null;
+    this.stageParametersId_ = 1;
+
+    this.service_ = service;
+
+    this.framesOfReference = {};
+
+    this.input_sources_ = new Map();
+    this.next_input_source_index_ = 1;
+
+    // Currently active hit test subscriptons.
+    this.hitTestSubscriptions_ = new Map();
+    // Currently active transient hit test subscriptions.
+    this.transientHitTestSubscriptions_ = new Map();
+    // ID of the next subscription to be assigned.
+    this.next_hit_test_id_ = 1n;
+
+    this.anchor_controllers_ = new Map();
+    // ID of the next anchor to be assigned.
+    this.next_anchor_id_ = 1n;
+    // Anchor creation callback (initially null, can be set by tests).
+    this.anchor_creation_callback_ = null;
+
+    this.depthSensingData_ = null;
+    this.depthSensingDataDirty_ = false;
+
+    let supportedModes = [];
+    if (fakeDeviceInit.supportedModes) {
+      supportedModes = fakeDeviceInit.supportedModes.slice();
+      if (fakeDeviceInit.supportedModes.length === 0) {
+        supportedModes = ["inline"];
+      }
+    } else {
+      // Back-compat mode.
+      console.warn("Please use `supportedModes` to signal which modes are supported by this device.");
+      if (fakeDeviceInit.supportsImmersive == null) {
+        throw new TypeError("'supportsImmersive' must be set");
+      }
+
+      supportedModes = ["inline"];
+      if (fakeDeviceInit.supportsImmersive) {
+        supportedModes.push("immersive-vr");
+      }
+    }
+
+    this.supportedModes_ = this._convertModesToEnum(supportedModes);
+    if (this.supportedModes_.length == 0) {
+      console.error("Device has empty supported modes array!");
+      throw new InvalidStateError();
+    }
+
+    if (fakeDeviceInit.viewerOrigin != null) {
+      this.setViewerOrigin(fakeDeviceInit.viewerOrigin);
+    }
+
+    if (fakeDeviceInit.floorOrigin != null) {
+      this.setFloorOrigin(fakeDeviceInit.floorOrigin);
+    }
+
+    if (fakeDeviceInit.world) {
+      this.setWorld(fakeDeviceInit.world);
+    }
+
+    if (fakeDeviceInit.depthSensingData) {
+      this.setDepthSensingData(fakeDeviceInit.depthSensingData);
+    }
+
+    this.defaultFramebufferScale_ = default_framebuffer_scale;
+    this.enviromentBlendMode_ = this._convertBlendModeToEnum(fakeDeviceInit.environmentBlendMode);
+    this.interactionMode_ = this._convertInteractionModeToEnum(fakeDeviceInit.interactionMode);
+
+    // This appropriately handles if the coordinates are null
+    this.setBoundsGeometry(fakeDeviceInit.boundsCoordinates);
+
+    this.setViews(fakeDeviceInit.views, fakeDeviceInit.secondaryViews);
+
+    // Need to support webVR which doesn't have a notion of features
+    this._setFeatures(fakeDeviceInit.supportedFeatures || []);
+  }
+
+  // WebXR Test API
+  setViews(primaryViews, secondaryViews) {
+    this.cameraImage_ = null;
+    this.primaryViews_ = [];
+    this.secondaryViews_ = [];
+    let xOffset = 0;
+    if (primaryViews) {
+      this.primaryViews_ = [];
+      xOffset = this._setViews(primaryViews, xOffset, this.primaryViews_);
+      const cameraImage = this._findCameraImage(primaryViews);
+
+      if (cameraImage) {
+        this.cameraImage_ = cameraImage;
+      }
+    }
+
+    if (secondaryViews) {
+      this.secondaryViews_ = [];
+      this._setViews(secondaryViews, xOffset, this.secondaryViews_);
+      const cameraImage = this._findCameraImage(secondaryViews);
+
+      if (cameraImage) {
+        if (!isSameCameraImageInit(this.cameraImage_, cameraImage)) {
+          throw new Error("If present, camera resolutions on each view must match each other!"
+                          + " Secondary views' camera doesn't match primary views.");
+        }
+
+        this.cameraImage_ = cameraImage;
+      }
+    }
+  }
+
+  disconnect() {
+    this.service_._removeRuntime(this);
+    this.presentation_provider_._close();
+    if (this.sessionClient_) {
+      this.sessionClient_.$.close();
+      this.sessionClient_ = null;
+    }
+
+    return Promise.resolve();
+  }
+
+  setViewerOrigin(origin, emulatedPosition = false) {
+    const p = origin.position;
+    const q = origin.orientation;
+    this.pose_ = {
+      orientation: { x: q[0], y: q[1], z: q[2], w: q[3] },
+      position: { x: p[0], y: p[1], z: p[2] },
+      emulatedPosition: emulatedPosition,
+      angularVelocity: null,
+      linearVelocity: null,
+      angularAcceleration: null,
+      linearAcceleration: null,
+      inputState: null,
+      poseIndex: 0
+    };
+  }
+
+  clearViewerOrigin() {
+    this.pose_ = null;
+  }
+
+  setFloorOrigin(floorOrigin) {
+    if (!this.stageParameters_) {
+      this.stageParameters_ = default_stage_parameters;
+      this.stageParameters_.bounds = this.bounds_;
+    }
+
+    // floorOrigin is passed in as mojoFromFloor.
+    this.stageParameters_.mojoFromFloor =
+        {matrix: getMatrixFromTransform(floorOrigin)};
+
+    this._onStageParametersUpdated();
+  }
+
+  clearFloorOrigin() {
+    if (this.stageParameters_) {
+      this.stageParameters_ = null;
+      this._onStageParametersUpdated();
+    }
+  }
+
+  setBoundsGeometry(bounds) {
+    if (bounds == null) {
+      this.bounds_ = null;
+    } else if (bounds.length < 3) {
+      throw new Error("Bounds must have a length of at least 3");
+    } else {
+      this.bounds_ = bounds;
+    }
+
+    // We can only set bounds if we have stageParameters set; otherwise, we
+    // don't know the transform from local space to bounds space.
+    // We'll cache the bounds so that they can be set in the future if the
+    // floorLevel transform is set, but we won't update them just yet.
+    if (this.stageParameters_) {
+      this.stageParameters_.bounds = this.bounds_;
+      this._onStageParametersUpdated();
+    }
+  }
+
+  simulateResetPose() {
+    this.send_mojo_space_reset_ = true;
+  }
+
+  simulateVisibilityChange(visibilityState) {
+    let mojoState = null;
+    switch (visibilityState) {
+      case "visible":
+        mojoState = vrMojom.XRVisibilityState.VISIBLE;
+        break;
+      case "visible-blurred":
+        mojoState = vrMojom.XRVisibilityState.VISIBLE_BLURRED;
+        break;
+      case "hidden":
+        mojoState = vrMojom.XRVisibilityState.HIDDEN;
+        break;
+    }
+    if (mojoState && this.sessionClient_) {
+      this.sessionClient_.onVisibilityStateChanged(mojoState);
+    }
+  }
+
+  simulateInputSourceConnection(fakeInputSourceInit) {
+    const index = this.next_input_source_index_;
+    this.next_input_source_index_++;
+
+    const source = new MockXRInputSource(fakeInputSourceInit, index, this);
+    this.input_sources_.set(index, source);
+    return source;
+  }
+
+  // WebXR Test API Hit Test extensions
+  setWorld(world) {
+    this.world_ = world;
+  }
+
+  clearWorld() {
+    this.world_ = null;
+  }
+
+  // WebXR Test API Anchor extensions
+  setAnchorCreationCallback(callback) {
+    this.anchor_creation_callback_ = callback;
+  }
+
+  setHitTestSourceCreationCallback(callback) {
+    this.hit_test_source_creation_callback_ = callback;
+  }
+
+  // WebXR Test API Lighting estimation extensions
+  setLightEstimate(fakeXrLightEstimateInit) {
+    if (!fakeXrLightEstimateInit.sphericalHarmonicsCoefficients) {
+      throw new TypeError("sphericalHarmonicsCoefficients must be set");
+    }
+
+    if (fakeXrLightEstimateInit.sphericalHarmonicsCoefficients.length != 27) {
+      throw new TypeError("Must supply all 27 sphericalHarmonicsCoefficients");
+    }
+
+    if (fakeXrLightEstimateInit.primaryLightDirection && fakeXrLightEstimateInit.primaryLightDirection.w != 0) {
+      throw new TypeError("W component of primaryLightDirection must be 0");
+    }
+
+    if (fakeXrLightEstimateInit.primaryLightIntensity && fakeXrLightEstimateInit.primaryLightIntensity.w != 1) {
+      throw new TypeError("W component of primaryLightIntensity must be 1");
+    }
+
+    // If the primaryLightDirection or primaryLightIntensity aren't set, we need to set them
+    // to the defaults that the spec expects. ArCore will either give us everything or nothing,
+    // so these aren't nullable on the mojom.
+    if (!fakeXrLightEstimateInit.primaryLightDirection) {
+      fakeXrLightEstimateInit.primaryLightDirection = { x: 0.0, y: 1.0, z: 0.0, w: 0.0 };
+    }
+
+    if (!fakeXrLightEstimateInit.primaryLightIntensity) {
+      fakeXrLightEstimateInit.primaryLightIntensity = { x: 0.0, y: 0.0, z: 0.0, w: 1.0 };
+    }
+
+    let c = fakeXrLightEstimateInit.sphericalHarmonicsCoefficients;
+
+    this.light_estimate_ = {
+      lightProbe: {
+        // XRSphereicalHarmonics
+        sphericalHarmonics: {
+          coefficients: [
+            { red: c[0],  green: c[1],  blue: c[2] },
+            { red: c[3],  green: c[4],  blue: c[5] },
+            { red: c[6],  green: c[7],  blue: c[8] },
+            { red: c[9],  green: c[10], blue: c[11] },
+            { red: c[12], green: c[13], blue: c[14] },
+            { red: c[15], green: c[16], blue: c[17] },
+            { red: c[18], green: c[19], blue: c[20] },
+            { red: c[21], green: c[22], blue: c[23] },
+            { red: c[24], green: c[25], blue: c[26] }
+          ]
+        },
+        // Vector3dF
+        mainLightDirection: {
+          x: fakeXrLightEstimateInit.primaryLightDirection.x,
+          y: fakeXrLightEstimateInit.primaryLightDirection.y,
+          z: fakeXrLightEstimateInit.primaryLightDirection.z
+        },
+        // RgbTupleF32
+        mainLightIntensity: {
+          red:   fakeXrLightEstimateInit.primaryLightIntensity.x,
+          green: fakeXrLightEstimateInit.primaryLightIntensity.y,
+          blue:  fakeXrLightEstimateInit.primaryLightIntensity.z
+        }
+      }
+    }
+  }
+
+  // WebXR Test API depth Sensing Extensions
+  setDepthSensingData(depthSensingData) {
+    for(const key of ["depthData", "normDepthBufferFromNormView", "rawValueToMeters", "width", "height"]) {
+      if(!(key in depthSensingData)) {
+        throw new TypeError("Required key not present. Key: " + key);
+      }
+    }
+
+    if(depthSensingData.depthData != null) {
+      // Create new object w/ properties based on the depthSensingData, but
+      // convert the FakeXRRigidTransformInit into a transformation matrix object.
+      this.depthSensingData_ = Object.assign({},
+        depthSensingData, {
+          normDepthBufferFromNormView: composeGFXTransform(depthSensingData.normDepthBufferFromNormView),
+        });
+    } else {
+      throw new TypeError("`depthData` is not set");
+    }
+
+    this.depthSensingDataDirty_ = true;
+  }
+
+  clearDepthSensingData() {
+    this.depthSensingData_ = null;
+    this.depthSensingDataDirty_ = true;
+  }
+
+  // Internal Implementation/Helper Methods
+  _convertModeToEnum(sessionMode) {
+    if (sessionMode in MockRuntime._sessionModeToMojoMap) {
+      return MockRuntime._sessionModeToMojoMap[sessionMode];
+    }
+
+    throw new TypeError("Unrecognized value for XRSessionMode enum: " + sessionMode);
+  }
+
+  _convertModesToEnum(sessionModes) {
+    return sessionModes.map(mode => this._convertModeToEnum(mode));
+  }
+
+  _convertBlendModeToEnum(blendMode) {
+    if (blendMode in MockRuntime._environmentBlendModeToMojoMap) {
+      return MockRuntime._environmentBlendModeToMojoMap[blendMode];
+    } else {
+      if (this.supportedModes_.includes(xrSessionMojom.XRSessionMode.kImmersiveAr)) {
+        return vrMojom.XREnvironmentBlendMode.kAdditive;
+      } else if (this.supportedModes_.includes(
+        xrSessionMojom.XRSessionMode.kImmersiveVr)) {
+        return vrMojom.XREnvironmentBlendMode.kOpaque;
+      }
+    }
+  }
+
+  _convertInteractionModeToEnum(interactionMode) {
+    if (interactionMode in MockRuntime._interactionModeToMojoMap) {
+      return MockRuntime._interactionModeToMojoMap[interactionMode];
+    } else {
+      return vrMojom.XRInteractionMode.kWorldSpace;
+    }
+  }
+
+  _setViews(deviceViews, xOffset, views) {
+    for (let i = 0; i < deviceViews.length; i++) {
+      views[i] = this._getView(deviceViews[i], xOffset);
+      xOffset += deviceViews[i].resolution.width;
+    }
+
+    return xOffset;
+  }
+
+  _findCameraImage(views) {
+    const viewWithCamera = views.find(view => view.cameraImageInit);
+    if (viewWithCamera) {
+      //If we have one view with a camera resolution, all views should have the same camera resolution.
+      const allViewsHaveSameCamera = views.every(
+        view => isSameCameraImageInit(view.cameraImageInit, viewWithCamera.cameraImageInit));
+
+      if (!allViewsHaveSameCamera) {
+        throw new Error("If present, camera resolutions on each view must match each other!");
+      }
+
+      return viewWithCamera.cameraImageInit;
+    }
+
+    return null;
+  }
+
+  _onStageParametersUpdated() {
+    // Indicate for the frame loop that the stage parameters have been updated.
+    this.stageParametersId_++;
+  }
+
+  _getDefaultViews() {
+    if (this.primaryViews_) {
+      return this.primaryViews_;
+    }
+
+    const viewport_size = 20;
+    return [{
+        eye: vrMojom.XREye.kLeft,
+        fieldOfView: {
+          upDegrees: 48.316,
+          downDegrees: 50.099,
+          leftDegrees: 50.899,
+          rightDegrees: 35.197
+        },
+        mojoFromView: this._getMojoFromViewerWithOffset(composeGFXTransform({
+          position: [-0.032, 0, 0],
+          orientation: [0, 0, 0, 1]
+        })),
+        viewport: { x: 0, y: 0, width: viewport_size, height: viewport_size }
+      },
+      {
+        eye: vrMojom.XREye.kRight,
+        fieldOfView: {
+          upDegrees: 48.316,
+          downDegrees: 50.099,
+          leftDegrees: 50.899,
+          rightDegrees: 35.197
+        },
+        mojoFromView: this._getMojoFromViewerWithOffset(composeGFXTransform({
+          position: [0.032, 0, 0],
+          orientation: [0, 0, 0, 1]
+        })),
+        viewport: { x: viewport_size, y: 0, width: viewport_size, height: viewport_size }
+      }];
+  }
+
+  // This function converts between the matrix provided by the WebXR test API
+  // and the internal data representation.
+  _getView(fakeXRViewInit, xOffset) {
+    let fov = null;
+
+    if (fakeXRViewInit.fieldOfView) {
+      fov = {
+        upDegrees: fakeXRViewInit.fieldOfView.upDegrees,
+        downDegrees: fakeXRViewInit.fieldOfView.downDegrees,
+        leftDegrees: fakeXRViewInit.fieldOfView.leftDegrees,
+        rightDegrees: fakeXRViewInit.fieldOfView.rightDegrees
+      };
+    } else {
+      const m = fakeXRViewInit.projectionMatrix;
+
+      function toDegrees(tan) {
+        return Math.atan(tan) * 180 / Math.PI;
+      }
+
+      const leftTan = (1 - m[8]) / m[0];
+      const rightTan = (1 + m[8]) / m[0];
+      const upTan = (1 + m[9]) / m[5];
+      const downTan = (1 - m[9]) / m[5];
+
+      fov = {
+        upDegrees: toDegrees(upTan),
+        downDegrees: toDegrees(downTan),
+        leftDegrees: toDegrees(leftTan),
+        rightDegrees: toDegrees(rightTan)
+      };
+    }
+
+    let viewEye = vrMojom.XREye.kNone;
+    // The eye passed in corresponds to the values in the WebXR spec, which are
+    // the strings "none", "left", and "right". They should be converted to the
+    // corresponding values of XREye in vr_service.mojom.
+    switch(fakeXRViewInit.eye) {
+      case "none":
+        viewEye = vrMojom.XREye.kNone;
+        break;
+      case "left":
+        viewEye = vrMojom.XREye.kLeft;
+        break;
+      case "right":
+        viewEye = vrMojom.XREye.kRight;
+        break;
+    }
+
+    return {
+      eye: viewEye,
+      fieldOfView: fov,
+      mojoFromView: this._getMojoFromViewerWithOffset(composeGFXTransform(fakeXRViewInit.viewOffset)),
+      viewport: {
+        x: xOffset,
+        y: 0,
+        width: fakeXRViewInit.resolution.width,
+        height: fakeXRViewInit.resolution.height
+      },
+      isFirstPersonObserver: fakeXRViewInit.isFirstPersonObserver ? true : false,
+      viewOffset: composeGFXTransform(fakeXRViewInit.viewOffset)
+    };
+  }
+
+  _setFeatures(supportedFeatures) {
+    function convertFeatureToMojom(feature) {
+      if (feature in MockRuntime._featureToMojoMap) {
+        return MockRuntime._featureToMojoMap[feature];
+      } else {
+        return xrSessionMojom.XRSessionFeature.INVALID;
+      }
+    }
+
+    this.supportedFeatures_ = [];
+
+    for (let i = 0; i < supportedFeatures.length; i++) {
+      const feature = convertFeatureToMojom(supportedFeatures[i]);
+      if (feature !== xrSessionMojom.XRSessionFeature.INVALID) {
+        this.supportedFeatures_.push(feature);
+      }
+    }
+  }
+
+  // These methods are intended to be used by MockXRInputSource only.
+  _addInputSource(source) {
+    if (!this.input_sources_.has(source.source_id_)) {
+      this.input_sources_.set(source.source_id_, source);
+    }
+  }
+
+  _removeInputSource(source) {
+    this.input_sources_.delete(source.source_id_);
+  }
+
+  // These methods are intended to be used by FakeXRAnchorController only.
+  _deleteAnchorController(controllerId) {
+    this.anchor_controllers_.delete(controllerId);
+  }
+
+  // Extension point for non-standard modules.
+  _injectAdditionalFrameData(options, frameData) {
+  }
+
+  // Mojo function implementations.
+
+  // XRFrameDataProvider implementation.
+  getFrameData(options) {
+    return new Promise((resolve) => {
+
+      const populatePose = () => {
+        const mojo_space_reset = this.send_mojo_space_reset_;
+        this.send_mojo_space_reset_ = false;
+
+        if (this.pose_) {
+          this.pose_.poseIndex++;
+        }
+
+        // Setting the input_state to null tests a slightly different path than
+        // the browser tests where if the last input source is removed, the device
+        // code always sends up an empty array, but it's also valid mojom to send
+        // up a null array.
+        let input_state = null;
+        if (this.input_sources_.size > 0) {
+          input_state = [];
+          for (const input_source of this.input_sources_.values()) {
+            input_state.push(input_source._getInputSourceState());
+          }
+        }
+
+        let frame_views = this.primaryViews_;
+        for (let i = 0; i < this.primaryViews_.length; i++) {
+          this.primaryViews_[i].mojoFromView =
+            this._getMojoFromViewerWithOffset(this.primaryViews_[i].viewOffset);
+        }
+        if (this.enabledFeatures_.includes(xrSessionMojom.XRSessionFeature.SECONDARY_VIEWS)) {
+          for (let i = 0; i < this.secondaryViews_.length; i++) {
+            this.secondaryViews_[i].mojoFromView =
+              this._getMojoFromViewerWithOffset(this.secondaryViews_[i].viewOffset);
+          }
+
+          frame_views = frame_views.concat(this.secondaryViews_);
+        }
+
+        const frameData = {
+          mojoFromViewer: this.pose_,
+          views: frame_views,
+          mojoSpaceReset: mojo_space_reset,
+          inputState: input_state,
+          timeDelta: {
+            // window.performance.now() is in milliseconds, so convert to microseconds.
+            microseconds: BigInt(Math.floor(window.performance.now() * 1000)),
+          },
+          frameId: this.next_frame_id_,
+          bufferHolder: null,
+          cameraImageSize: this.cameraImage_ ? {
+            width: this.cameraImage_.width,
+            height: this.cameraImage_.height
+          } : null,
+          renderingTimeRatio: 0,
+          stageParameters: this.stageParameters_,
+          stageParametersId: this.stageParametersId_,
+          lightEstimationData: this.light_estimate_
+        };
+
+        this.next_frame_id_++;
+
+        this._calculateHitTestResults(frameData);
+
+        this._calculateAnchorInformation(frameData);
+
+        this._calculateDepthInformation(frameData);
+
+        this._injectAdditionalFrameData(options, frameData);
+
+        resolve({frameData});
+      };
+
+      if(this.sessionOptions_.mode == xrSessionMojom.XRSessionMode.kInline) {
+        // Inline sessions should not have a delay introduced since it causes them
+        // to miss a vsync blink-side and delays propagation of changes that happened
+        // within a rAFcb by one frame (e.g. setViewerOrigin() calls would take 2 frames
+        // to propagate).
+        populatePose();
+      } else {
+        // For immerive sessions, add additional delay to allow for anchor creation
+        // promises to run.
+        setTimeout(populatePose, 3);  // note: according to MDN, the timeout is not exact
+      }
+    });
+  }
+
+  getEnvironmentIntegrationProvider(environmentProviderRequest) {
+    if (this.environmentProviderReceiver_) {
+      this.environmentProviderReceiver_.$.close();
+    }
+    this.environmentProviderReceiver_ =
+        new vrMojom.XREnvironmentIntegrationProviderReceiver(this);
+    this.environmentProviderReceiver_.$.bindHandle(
+        environmentProviderRequest.handle);
+  }
+
+  setInputSourceButtonListener(listener) { listener.$.close(); }
+
+  // XREnvironmentIntegrationProvider implementation:
+  subscribeToHitTest(nativeOriginInformation, entityTypes, ray) {
+    if (!this.supportedModes_.includes(xrSessionMojom.XRSessionMode.kImmersiveAr)) {
+      // Reject outside of AR.
+      return Promise.resolve({
+        result : vrMojom.SubscribeToHitTestResult.FAILURE_GENERIC,
+        subscriptionId : 0n
+      });
+    }
+
+    if (!this._nativeOriginKnown(nativeOriginInformation)) {
+      return Promise.resolve({
+        result : vrMojom.SubscribeToHitTestResult.FAILURE_GENERIC,
+        subscriptionId : 0n
+      });
+    }
+
+    // Reserve the id for hit test source:
+    const id = this.next_hit_test_id_++;
+    const hitTestParameters = { isTransient: false, profileName: null };
+    const controller = new FakeXRHitTestSourceController(id);
+
+
+    return this._shouldHitTestSourceCreationSucceed(hitTestParameters, controller)
+      .then((succeeded) => {
+        if(succeeded) {
+          // Store the subscription information as-is (including controller):
+          this.hitTestSubscriptions_.set(id, { nativeOriginInformation, entityTypes, ray, controller });
+
+          return Promise.resolve({
+            result : vrMojom.SubscribeToHitTestResult.SUCCESS,
+            subscriptionId : id
+          });
+        } else {
+          return Promise.resolve({
+            result : vrMojom.SubscribeToHitTestResult.FAILURE_GENERIC,
+            subscriptionId : 0n
+          });
+        }
+      });
+  }
+
+  subscribeToHitTestForTransientInput(profileName, entityTypes, ray){
+    if (!this.supportedModes_.includes(xrSessionMojom.XRSessionMode.kImmersiveAr)) {
+      // Reject outside of AR.
+      return Promise.resolve({
+        result : vrMojom.SubscribeToHitTestResult.FAILURE_GENERIC,
+        subscriptionId : 0n
+      });
+    }
+
+    const id = this.next_hit_test_id_++;
+    const hitTestParameters = { isTransient: true, profileName: profileName };
+    const controller = new FakeXRHitTestSourceController(id);
+
+    // Check if we have hit test source creation callback.
+    // If yes, ask it if the hit test source creation should succeed.
+    // If no, for back-compat, assume the hit test source creation succeeded.
+    return this._shouldHitTestSourceCreationSucceed(hitTestParameters, controller)
+      .then((succeeded) => {
+        if(succeeded) {
+          // Store the subscription information as-is (including controller):
+          this.transientHitTestSubscriptions_.set(id, { profileName, entityTypes, ray, controller });
+
+          return Promise.resolve({
+            result : vrMojom.SubscribeToHitTestResult.SUCCESS,
+            subscriptionId : id
+          });
+        } else {
+          return Promise.resolve({
+            result : vrMojom.SubscribeToHitTestResult.FAILURE_GENERIC,
+            subscriptionId : 0n
+          });
+        }
+      });
+  }
+
+  unsubscribeFromHitTest(subscriptionId) {
+    let controller = null;
+    if(this.transientHitTestSubscriptions_.has(subscriptionId)){
+      controller = this.transientHitTestSubscriptions_.get(subscriptionId).controller;
+      this.transientHitTestSubscriptions_.delete(subscriptionId);
+    } else if(this.hitTestSubscriptions_.has(subscriptionId)){
+      controller = this.hitTestSubscriptions_.get(subscriptionId).controller;
+      this.hitTestSubscriptions_.delete(subscriptionId);
+    }
+
+    if(controller) {
+      controller.deleted = true;
+    }
+  }
+
+  createAnchor(nativeOriginInformation, nativeOriginFromAnchor) {
+    return new Promise((resolve) => {
+      if(this.anchor_creation_callback_ == null) {
+        resolve({
+          result : vrMojom.CreateAnchorResult.FAILURE,
+          anchorId : 0n
+        });
+
+        return;
+      }
+
+      const mojoFromNativeOrigin = this._getMojoFromNativeOrigin(nativeOriginInformation);
+      if(mojoFromNativeOrigin == null) {
+        resolve({
+          result : vrMojom.CreateAnchorResult.FAILURE,
+          anchorId : 0n
+        });
+
+        return;
+      }
+
+      const mojoFromAnchor = XRMathHelper.mul4x4(mojoFromNativeOrigin, nativeOriginFromAnchor);
+
+      const anchorCreationParameters = {
+        requestedAnchorOrigin: mojoFromAnchor,
+        isAttachedToEntity: false,
+      };
+
+      const anchorController = new FakeXRAnchorController();
+
+      this.anchor_creation_callback_(anchorCreationParameters, anchorController)
+            .then((result) => {
+              if(result) {
+                // If the test allowed the anchor creation,
+                // store the anchor controller & return success.
+
+                const anchor_id = this.next_anchor_id_;
+                this.next_anchor_id_++;
+
+                this.anchor_controllers_.set(anchor_id, anchorController);
+                anchorController.device = this;
+                anchorController.id = anchor_id;
+
+                resolve({
+                  result : vrMojom.CreateAnchorResult.SUCCESS,
+                  anchorId : anchor_id
+                });
+              } else {
+                // The test has rejected anchor creation.
+                resolve({
+                  result : vrMojom.CreateAnchorResult.FAILURE,
+                  anchorId : 0n
+                });
+              }
+            })
+            .catch(() => {
+              // The test threw an error, treat anchor creation as failed.
+              resolve({
+                result : vrMojom.CreateAnchorResult.FAILURE,
+                anchorId : 0n
+              });
+            });
+    });
+  }
+
+  createPlaneAnchor(planeFromAnchor, planeId) {
+    return new Promise((resolve) => {
+
+      // Not supported yet.
+
+      resolve({
+        result : vrMojom.CreateAnchorResult.FAILURE,
+        anchorId : 0n,
+      });
+    });
+  }
+
+  detachAnchor(anchorId) {}
+
+  // Utility function
+  _requestRuntimeSession(sessionOptions) {
+    return this._runtimeSupportsSession(sessionOptions).then((result) => {
+      // The JavaScript bindings convert c_style_names to camelCase names.
+      const options = {
+        transportMethod:
+            vrMojom.XRPresentationTransportMethod.SUBMIT_AS_MAILBOX_HOLDER,
+        waitForTransferNotification: true,
+        waitForRenderNotification: true,
+        waitForGpuFence: false,
+      };
+
+      let submit_frame_sink;
+      if (result.supportsSession) {
+        submit_frame_sink = {
+          clientReceiver: this.presentation_provider_._getClientReceiver(),
+          provider: this.presentation_provider_._bindProvider(sessionOptions),
+          transportOptions: options
+        };
+
+        const dataProviderPtr = new vrMojom.XRFrameDataProviderRemote();
+        this.dataProviderReceiver_ =
+            new vrMojom.XRFrameDataProviderReceiver(this);
+        this.dataProviderReceiver_.$.bindHandle(
+            dataProviderPtr.$.bindNewPipeAndPassReceiver().handle);
+        this.sessionOptions_ = sessionOptions;
+
+        this.sessionClient_ = new vrMojom.XRSessionClientRemote();
+        const clientReceiver = this.sessionClient_.$.bindNewPipeAndPassReceiver();
+
+        const enabled_features = [];
+        for (let i = 0; i < sessionOptions.requiredFeatures.length; i++) {
+          if (this.supportedFeatures_.indexOf(sessionOptions.requiredFeatures[i]) !== -1) {
+            enabled_features.push(sessionOptions.requiredFeatures[i]);
+          } else {
+            return Promise.resolve({session: null});
+          }
+        }
+
+        for (let i =0; i < sessionOptions.optionalFeatures.length; i++) {
+          if (this.supportedFeatures_.indexOf(sessionOptions.optionalFeatures[i]) !== -1) {
+            enabled_features.push(sessionOptions.optionalFeatures[i]);
+          }
+        }
+
+        this.enabledFeatures_ = enabled_features;
+
+        return Promise.resolve({
+          session: {
+            submitFrameSink: submit_frame_sink,
+            dataProvider: dataProviderPtr,
+            clientReceiver: clientReceiver,
+            enabledFeatures: enabled_features,
+            deviceConfig: {
+              usesInputEventing: false,
+              defaultFramebufferScale: this.defaultFramebufferScale_,
+              supportsViewportScaling: true,
+              depthConfiguration:
+                enabled_features.includes(xrSessionMojom.XRSessionFeature.DEPTH) ? {
+                  depthUsage: vrMojom.XRDepthUsage.kCPUOptimized,
+                  depthDataFormat: vrMojom.XRDepthDataFormat.kLuminanceAlpha,
+                } : null,
+              views: this._getDefaultViews(),
+            },
+            enviromentBlendMode: this.enviromentBlendMode_,
+            interactionMode: this.interactionMode_
+          }
+        });
+      } else {
+        return Promise.resolve({session: null});
+      }
+    });
+  }
+
+  _runtimeSupportsSession(options) {
+    let result = this.supportedModes_.includes(options.mode);
+
+    if (options.requiredFeatures.includes(xrSessionMojom.XRSessionFeature.DEPTH)
+    || options.optionalFeatures.includes(xrSessionMojom.XRSessionFeature.DEPTH)) {
+      result &= options.depthOptions.usagePreferences.includes(vrMojom.XRDepthUsage.kCPUOptimized);
+      result &= options.depthOptions.dataFormatPreferences.includes(vrMojom.XRDepthDataFormat.kLuminanceAlpha);
+    }
+
+    return Promise.resolve({
+      supportsSession: result,
+    });
+  }
+
+  // Private functions - utilities:
+  _nativeOriginKnown(nativeOriginInformation){
+
+    if (nativeOriginInformation.inputSourceSpaceInfo !== undefined) {
+      if (!this.input_sources_.has(nativeOriginInformation.inputSourceSpaceInfo.inputSourceId)) {
+        // Unknown input source.
+        return false;
+      }
+
+      return true;
+    } else if (nativeOriginInformation.referenceSpaceType !== undefined) {
+      // Bounded_floor & unbounded ref spaces are not yet supported for AR:
+      if (nativeOriginInformation.referenceSpaceType == vrMojom.XRReferenceSpaceType.kUnbounded
+       || nativeOriginInformation.referenceSpaceType == vrMojom.XRReferenceSpaceType.kBoundedFloor) {
+        return false;
+      }
+
+      return true;
+    } else {
+      // Planes and anchors are not yet supported by the mock interface.
+      return false;
+    }
+  }
+
+  // Private functions - anchors implementation:
+
+  // Modifies passed in frameData to add anchor information.
+  _calculateAnchorInformation(frameData) {
+    if (!this.supportedModes_.includes(xrSessionMojom.XRSessionMode.kImmersiveAr)) {
+      return;
+    }
+
+    frameData.anchorsData = {allAnchorsIds: [], updatedAnchorsData: []};
+    for(const [id, controller] of this.anchor_controllers_) {
+      frameData.anchorsData.allAnchorsIds.push(id);
+
+      // Send the entire anchor data over if there was a change since last GetFrameData().
+      if(controller.dirty) {
+        const anchorData = {id};
+        if(!controller.paused) {
+          anchorData.mojoFromAnchor = getPoseFromTransform(
+              XRMathHelper.decomposeRigidTransform(
+                  controller._getAnchorOrigin()));
+        }
+
+        controller._markProcessed();
+
+        frameData.anchorsData.updatedAnchorsData.push(anchorData);
+      }
+    }
+  }
+
+  // Private functions - depth sensing implementation:
+
+  // Modifies passed in frameData to add anchor information.
+  _calculateDepthInformation(frameData) {
+    if (!this.supportedModes_.includes(xrSessionMojom.XRSessionMode.kImmersiveAr)) {
+      return;
+    }
+
+    if (!this.enabledFeatures_.includes(xrSessionMojom.XRSessionFeature.DEPTH)) {
+      return;
+    }
+
+    // If we don't have a current depth data, we'll return null
+    // (i.e. no data is not a valid data, so it cannot be "StillValid").
+    if (this.depthSensingData_ == null) {
+      frameData.depthData = null;
+      return;
+    }
+
+    if(!this.depthSensingDataDirty_) {
+      frameData.depthData = { dataStillValid: {}};
+      return;
+    }
+
+    frameData.depthData = {
+      updatedDepthData: {
+        timeDelta: frameData.timeDelta,
+        normTextureFromNormView: this.depthSensingData_.normDepthBufferFromNormView,
+        rawValueToMeters: this.depthSensingData_.rawValueToMeters,
+        size: { width: this.depthSensingData_.width, height: this.depthSensingData_.height },
+        pixelData: { bytes: this.depthSensingData_.depthData }
+      }
+    };
+
+    this.depthSensingDataDirty_ = false;
+  }
+
+  // Private functions - hit test implementation:
+
+  // Returns a Promise<bool> that signifies whether hit test source creation should succeed.
+  // If we have a hit test source creation callback installed, invoke it and return its result.
+  // If it's not installed, for back-compat just return a promise that resolves to true.
+  _shouldHitTestSourceCreationSucceed(hitTestParameters, controller) {
+    if(this.hit_test_source_creation_callback_) {
+      return this.hit_test_source_creation_callback_(hitTestParameters, controller);
+    } else {
+      return Promise.resolve(true);
+    }
+  }
+
+  // Modifies passed in frameData to add hit test results.
+  _calculateHitTestResults(frameData) {
+    if (!this.supportedModes_.includes(xrSessionMojom.XRSessionMode.kImmersiveAr)) {
+      return;
+    }
+
+    frameData.hitTestSubscriptionResults = {results: [],
+                                            transientInputResults: []};
+    if (!this.world_) {
+      return;
+    }
+
+    // Non-transient hit test:
+    for (const [id, subscription] of this.hitTestSubscriptions_) {
+      const mojo_from_native_origin = this._getMojoFromNativeOrigin(subscription.nativeOriginInformation);
+      if (!mojo_from_native_origin) continue;
+
+      const [mojo_ray_origin, mojo_ray_direction] = this._transformRayToMojoSpace(
+        subscription.ray,
+        mojo_from_native_origin
+      );
+
+      const results = this._hitTestWorld(mojo_ray_origin, mojo_ray_direction, subscription.entityTypes);
+      frameData.hitTestSubscriptionResults.results.push(
+          {subscriptionId: id, hitTestResults: results});
+    }
+
+    // Transient hit test:
+    const mojo_from_viewer = this._getMojoFromViewer();
+
+    for (const [id, subscription] of this.transientHitTestSubscriptions_) {
+      const result = {subscriptionId: id,
+                      inputSourceIdToHitTestResults: new Map()};
+
+      // Find all input sources that match the profile name:
+      const matching_input_sources = Array.from(this.input_sources_.values())
+                                                        .filter(input_source => input_source.profiles_.includes(subscription.profileName));
+
+      for (const input_source of matching_input_sources) {
+        const mojo_from_native_origin = input_source._getMojoFromInputSource(mojo_from_viewer);
+
+        const [mojo_ray_origin, mojo_ray_direction] = this._transformRayToMojoSpace(
+          subscription.ray,
+          mojo_from_native_origin
+        );
+
+        const results = this._hitTestWorld(mojo_ray_origin, mojo_ray_direction, subscription.entityTypes);
+
+        result.inputSourceIdToHitTestResults.set(input_source.source_id_, results);
+      }
+
+      frameData.hitTestSubscriptionResults.transientInputResults.push(result);
+    }
+  }
+
+  // Returns 2-element array [origin, direction] of a ray in mojo space.
+  // |ray| is expressed relative to native origin.
+  _transformRayToMojoSpace(ray, mojo_from_native_origin) {
+    const ray_origin = {
+      x: ray.origin.x,
+      y: ray.origin.y,
+      z: ray.origin.z,
+      w: 1
+    };
+    const ray_direction = {
+      x: ray.direction.x,
+      y: ray.direction.y,
+      z: ray.direction.z,
+      w: 0
+    };
+
+    const mojo_ray_origin = XRMathHelper.transform_by_matrix(
+      mojo_from_native_origin,
+      ray_origin);
+    const mojo_ray_direction = XRMathHelper.transform_by_matrix(
+      mojo_from_native_origin,
+      ray_direction);
+
+    return [mojo_ray_origin, mojo_ray_direction];
+  }
+
+  // Hit tests the passed in ray (expressed as origin and direction) against the mocked world data.
+  _hitTestWorld(origin, direction, entityTypes) {
+    let result = [];
+
+    for (const region of this.world_.hitTestRegions) {
+      const partial_result = this._hitTestRegion(
+        region,
+        origin, direction,
+        entityTypes);
+
+      result = result.concat(partial_result);
+    }
+
+    return result.sort((lhs, rhs) => lhs.distance - rhs.distance).map((hitTest) => {
+      delete hitTest.distance;
+      return hitTest;
+    });
+  }
+
+  // Hit tests the passed in ray (expressed as origin and direction) against world region.
+  // |entityTypes| is a set of FakeXRRegionTypes.
+  // |region| is FakeXRRegion.
+  // Returns array of XRHitResults, each entry will be decorated with the distance from the ray origin (along the ray).
+  _hitTestRegion(region, origin, direction, entityTypes) {
+    const regionNameToMojoEnum = {
+      "point": vrMojom.EntityTypeForHitTest.POINT,
+      "plane": vrMojom.EntityTypeForHitTest.PLANE,
+      "mesh":null
+    };
+
+    if (!entityTypes.includes(regionNameToMojoEnum[region.type])) {
+      return [];
+    }
+
+    const result = [];
+    for (const face of region.faces) {
+      const maybe_hit = this._hitTestFace(face, origin, direction);
+      if (maybe_hit) {
+        result.push(maybe_hit);
+      }
+    }
+
+    // The results should be sorted by distance and there should be no 2 entries with
+    // the same distance from ray origin - that would mean they are the same point.
+    // This situation is possible when a ray intersects the region through an edge shared
+    // by 2 faces.
+    return result.sort((lhs, rhs) => lhs.distance - rhs.distance)
+                 .filter((val, index, array) => index === 0 || val.distance !== array[index - 1].distance);
+  }
+
+  // Hit tests the passed in ray (expressed as origin and direction) against a single face.
+  // |face|, |origin|, and |direction| are specified in world (aka mojo) coordinates.
+  // |face| is an array of DOMPointInits.
+  // Returns null if the face does not intersect with the ray, otherwise the result is
+  // an XRHitResult with matrix describing the pose of the intersection point.
+  _hitTestFace(face, origin, direction) {
+    const add = XRMathHelper.add;
+    const sub = XRMathHelper.sub;
+    const mul = XRMathHelper.mul;
+    const normalize = XRMathHelper.normalize;
+    const dot = XRMathHelper.dot;
+    const cross = XRMathHelper.cross;
+    const neg = XRMathHelper.neg;
+
+    //1. Calculate plane normal in world coordinates.
+    const point_A = face.vertices[0];
+    const point_B = face.vertices[1];
+    const point_C = face.vertices[2];
+
+    const edge_AB = sub(point_B, point_A);
+    const edge_AC = sub(point_C, point_A);
+
+    const normal = normalize(cross(edge_AB, edge_AC));
+
+    const numerator = dot(sub(point_A, origin), normal);
+    const denominator = dot(direction, normal);
+
+    if (Math.abs(denominator) < XRMathHelper.EPSILON) {
+      // Planes are nearly parallel - there's either infinitely many intersection points or 0.
+      // Both cases signify a "no hit" for us.
+      return null;
+    } else {
+      // Single intersection point between the infinite plane and the line (*not* ray).
+      // Need to calculate the hit test matrix taking into account the face vertices.
+      const distance = numerator / denominator;
+      if (distance < 0) {
+        // Line - plane intersection exists, but not the half-line - plane does not.
+        return null;
+      } else {
+        const intersection_point = add(origin, mul(distance, direction));
+        // Since we are treating the face as a solid, flip the normal so that its
+        // half-space will contain the ray origin.
+        const y_axis = denominator > 0 ? neg(normal) : normal;
+
+        let z_axis = null;
+        const cos_direction_and_y_axis = dot(direction, y_axis);
+        if (Math.abs(cos_direction_and_y_axis) > (1 - XRMathHelper.EPSILON)) {
+          // Ray and the hit test normal are co-linear - try using the 'up' or 'right' vector's projection on the face plane as the Z axis.
+          // Note: this edge case is currently not covered by the spec.
+          const up = {x: 0.0, y: 1.0, z: 0.0, w: 0.0};
+          const right = {x: 1.0, y: 0.0, z: 0.0, w: 0.0};
+
+          z_axis = Math.abs(dot(up, y_axis)) > (1 - XRMathHelper.EPSILON)
+                        ? sub(up, mul(dot(right, y_axis), y_axis))  // `up is also co-linear with hit test normal, use `right`
+                        : sub(up, mul(dot(up, y_axis), y_axis));    // `up` is not co-linear with hit test normal, use it
+        } else {
+          // Project the ray direction onto the plane, negate it and use as a Z axis.
+          z_axis = neg(sub(direction, mul(cos_direction_and_y_axis, y_axis))); // Z should point towards the ray origin, not away.
+        }
+
+        z_axis = normalize(z_axis);
+        const x_axis = normalize(cross(y_axis, z_axis));
+
+        // Filter out the points not in polygon.
+        if (!XRMathHelper.pointInFace(intersection_point, face)) {
+          return null;
+        }
+
+        const hitResult = {planeId: 0n};
+        hitResult.distance = distance;  // Extend the object with additional information used by higher layers.
+                                        // It will not be serialized over mojom.
+
+        const matrix = new Array(16);
+
+        matrix[0] = x_axis.x;
+        matrix[1] = x_axis.y;
+        matrix[2] = x_axis.z;
+        matrix[3] = 0;
+
+        matrix[4] = y_axis.x;
+        matrix[5] = y_axis.y;
+        matrix[6] = y_axis.z;
+        matrix[7] = 0;
+
+        matrix[8] = z_axis.x;
+        matrix[9] = z_axis.y;
+        matrix[10] = z_axis.z;
+        matrix[11] = 0;
+
+        matrix[12] = intersection_point.x;
+        matrix[13] = intersection_point.y;
+        matrix[14] = intersection_point.z;
+        matrix[15] = 1;
+
+        hitResult.mojoFromResult = getPoseFromTransform(
+            XRMathHelper.decomposeRigidTransform(matrix));
+        return hitResult;
+      }
+    }
+  }
+
+  _getMojoFromViewer() {
+    if (!this.pose_) {
+      return XRMathHelper.identity();
+    }
+    const transform = {
+      position: [
+        this.pose_.position.x,
+        this.pose_.position.y,
+        this.pose_.position.z],
+      orientation: [
+        this.pose_.orientation.x,
+        this.pose_.orientation.y,
+        this.pose_.orientation.z,
+        this.pose_.orientation.w],
+    };
+
+    return getMatrixFromTransform(transform);
+  }
+
+  _getMojoFromViewerWithOffset(viewOffset) {
+    return { matrix: XRMathHelper.mul4x4(this._getMojoFromViewer(), viewOffset.matrix) };
+  }
+
+  _getMojoFromNativeOrigin(nativeOriginInformation) {
+    const mojo_from_viewer = this._getMojoFromViewer();
+
+    if (nativeOriginInformation.inputSourceSpaceInfo !== undefined) {
+      if (!this.input_sources_.has(nativeOriginInformation.inputSourceSpaceInfo.inputSourceId)) {
+        return null;
+      } else {
+        const inputSource = this.input_sources_.get(nativeOriginInformation.inputSourceSpaceInfo.inputSourceId);
+        return inputSource._getMojoFromInputSource(mojo_from_viewer);
+      }
+    } else if (nativeOriginInformation.referenceSpaceType !== undefined) {
+      switch (nativeOriginInformation.referenceSpaceType) {
+        case vrMojom.XRReferenceSpaceType.kLocal:
+          return XRMathHelper.identity();
+        case vrMojom.XRReferenceSpaceType.kLocalFloor:
+          if (this.stageParameters_ == null || this.stageParameters_.mojoFromFloor == null) {
+            console.warn("Standing transform not available.");
+            return null;
+          }
+          return this.stageParameters_.mojoFromFloor.matrix;
+        case vrMojom.XRReferenceSpaceType.kViewer:
+          return mojo_from_viewer;
+        case vrMojom.XRReferenceSpaceType.kBoundedFloor:
+          return null;
+        case vrMojom.XRReferenceSpaceType.kUnbounded:
+          return null;
+        default:
+          throw new TypeError("Unrecognized XRReferenceSpaceType!");
+      }
+    } else {
+      // Anchors & planes are not yet supported for hit test.
+      return null;
+    }
+  }
+}
+
+class MockXRInputSource {
+  constructor(fakeInputSourceInit, id, pairedDevice) {
+    this.source_id_ = id;
+    this.pairedDevice_ = pairedDevice;
+    this.handedness_ = fakeInputSourceInit.handedness;
+    this.target_ray_mode_ = fakeInputSourceInit.targetRayMode;
+
+    if (fakeInputSourceInit.pointerOrigin == null) {
+      throw new TypeError("FakeXRInputSourceInit.pointerOrigin is required.");
+    }
+
+    this.setPointerOrigin(fakeInputSourceInit.pointerOrigin);
+    this.setProfiles(fakeInputSourceInit.profiles);
+
+    this.primary_input_pressed_ = false;
+    if (fakeInputSourceInit.selectionStarted != null) {
+      this.primary_input_pressed_ = fakeInputSourceInit.selectionStarted;
+    }
+
+    this.primary_input_clicked_ = false;
+    if (fakeInputSourceInit.selectionClicked != null) {
+      this.primary_input_clicked_ = fakeInputSourceInit.selectionClicked;
+    }
+
+    this.primary_squeeze_pressed_ = false;
+    this.primary_squeeze_clicked_ = false;
+
+    this.mojo_from_input_ = null;
+    if (fakeInputSourceInit.gripOrigin != null) {
+      this.setGripOrigin(fakeInputSourceInit.gripOrigin);
+    }
+
+    // This properly handles if supportedButtons were not specified.
+    this.setSupportedButtons(fakeInputSourceInit.supportedButtons);
+
+    this.emulated_position_ = false;
+    this.desc_dirty_ = true;
+  }
+
+  // WebXR Test API
+  setHandedness(handedness) {
+    if (this.handedness_ != handedness) {
+      this.desc_dirty_ = true;
+      this.handedness_ = handedness;
+    }
+  }
+
+  setTargetRayMode(targetRayMode) {
+    if (this.target_ray_mode_ != targetRayMode) {
+      this.desc_dirty_ = true;
+      this.target_ray_mode_ = targetRayMode;
+    }
+  }
+
+  setProfiles(profiles) {
+    this.desc_dirty_ = true;
+    this.profiles_ = profiles;
+  }
+
+  setGripOrigin(transform, emulatedPosition = false) {
+    // grip_origin was renamed to mojo_from_input in mojo
+    this.mojo_from_input_ = composeGFXTransform(transform);
+    this.emulated_position_ = emulatedPosition;
+
+    // Technically, setting the grip shouldn't make the description dirty, but
+    // the webxr-test-api sets our pointer as mojoFromPointer; however, we only
+    // support it across mojom as inputFromPointer, so we need to recalculate it
+    // whenever the grip moves.
+    this.desc_dirty_ = true;
+  }
+
+  clearGripOrigin() {
+    // grip_origin was renamed to mojo_from_input in mojo
+    if (this.mojo_from_input_ != null) {
+      this.mojo_from_input_ = null;
+      this.emulated_position_ = false;
+      this.desc_dirty_ = true;
+    }
+  }
+
+  setPointerOrigin(transform, emulatedPosition = false) {
+    // pointer_origin is mojo_from_pointer.
+    this.desc_dirty_ = true;
+    this.mojo_from_pointer_ = composeGFXTransform(transform);
+    this.emulated_position_ = emulatedPosition;
+  }
+
+  disconnect() {
+    this.pairedDevice_._removeInputSource(this);
+  }
+
+  reconnect() {
+    this.pairedDevice_._addInputSource(this);
+  }
+
+  startSelection() {
+    this.primary_input_pressed_ = true;
+    if (this.gamepad_) {
+      this.gamepad_.buttons[0].pressed = true;
+      this.gamepad_.buttons[0].touched = true;
+    }
+  }
+
+  endSelection() {
+    if (!this.primary_input_pressed_) {
+      throw new Error("Attempted to end selection which was not started");
+    }
+
+    this.primary_input_pressed_ = false;
+    this.primary_input_clicked_ = true;
+
+    if (this.gamepad_) {
+      this.gamepad_.buttons[0].pressed = false;
+      this.gamepad_.buttons[0].touched = false;
+    }
+  }
+
+  simulateSelect() {
+    this.primary_input_clicked_ = true;
+  }
+
+  setSupportedButtons(supportedButtons) {
+    this.gamepad_ = null;
+    this.supported_buttons_ = [];
+
+    // If there are no supported buttons, we can stop now.
+    if (supportedButtons == null || supportedButtons.length < 1) {
+      return;
+    }
+
+    const supported_button_map = {};
+    this.gamepad_ = this._getEmptyGamepad();
+    for (let i = 0; i < supportedButtons.length; i++) {
+      const buttonType = supportedButtons[i].buttonType;
+      this.supported_buttons_.push(buttonType);
+      supported_button_map[buttonType] = supportedButtons[i];
+    }
+
+    // Let's start by building the button state in order of priority:
+    // Primary button is index 0.
+    this.gamepad_.buttons.push({
+      pressed: this.primary_input_pressed_,
+      touched: this.primary_input_pressed_,
+      value: this.primary_input_pressed_ ? 1.0 : 0.0
+    });
+
+    // Now add the rest of our buttons
+    this._addGamepadButton(supported_button_map['grip']);
+    this._addGamepadButton(supported_button_map['touchpad']);
+    this._addGamepadButton(supported_button_map['thumbstick']);
+    this._addGamepadButton(supported_button_map['optional-button']);
+    this._addGamepadButton(supported_button_map['optional-thumbstick']);
+
+    // Finally, back-fill placeholder buttons/axes
+    for (let i = 0; i < this.gamepad_.buttons.length; i++) {
+      if (this.gamepad_.buttons[i] == null) {
+        this.gamepad_.buttons[i] = {
+          pressed: false,
+          touched: false,
+          value: 0
+        };
+      }
+    }
+
+    for (let i=0; i < this.gamepad_.axes.length; i++) {
+      if (this.gamepad_.axes[i] == null) {
+        this.gamepad_.axes[i] = 0;
+      }
+    }
+  }
+
+  updateButtonState(buttonState) {
+    if (this.supported_buttons_.indexOf(buttonState.buttonType) == -1) {
+      throw new Error("Tried to update state on an unsupported button");
+    }
+
+    const buttonIndex = this._getButtonIndex(buttonState.buttonType);
+    const axesStartIndex = this._getAxesStartIndex(buttonState.buttonType);
+
+    if (buttonIndex == -1) {
+      throw new Error("Unknown Button Type!");
+    }
+
+    // is this a 'squeeze' button?
+    if (buttonIndex === this._getButtonIndex('grip')) {
+      // squeeze
+      if (buttonState.pressed) {
+        this.primary_squeeze_pressed_ = true;
+      } else if (this.gamepad_.buttons[buttonIndex].pressed) {
+        this.primary_squeeze_clicked_ = true;
+        this.primary_squeeze_pressed_ = false;
+      } else {
+        this.primary_squeeze_clicked_ = false;
+        this.primary_squeeze_pressed_ = false;
+      }
+    }
+
+    this.gamepad_.buttons[buttonIndex].pressed = buttonState.pressed;
+    this.gamepad_.buttons[buttonIndex].touched = buttonState.touched;
+    this.gamepad_.buttons[buttonIndex].value = buttonState.pressedValue;
+
+    if (axesStartIndex != -1) {
+      this.gamepad_.axes[axesStartIndex] = buttonState.xValue == null ? 0.0 : buttonState.xValue;
+      this.gamepad_.axes[axesStartIndex + 1] = buttonState.yValue == null ? 0.0 : buttonState.yValue;
+    }
+  }
+
+  // DOM Overlay Extensions
+  setOverlayPointerPosition(x, y) {
+    this.overlay_pointer_position_ = {x: x, y: y};
+  }
+
+  // Helpers for Mojom
+  _getInputSourceState() {
+    const input_state = {};
+
+    input_state.sourceId = this.source_id_;
+    input_state.isAuxiliary = false;
+
+    input_state.primaryInputPressed = this.primary_input_pressed_;
+    input_state.primaryInputClicked = this.primary_input_clicked_;
+
+    input_state.primarySqueezePressed = this.primary_squeeze_pressed_;
+    input_state.primarySqueezeClicked = this.primary_squeeze_clicked_;
+    // Setting the input source's "clicked" state should generate one "select"
+    // event. Reset the input value to prevent it from continuously generating
+    // events.
+    this.primary_input_clicked_ = false;
+    // Setting the input source's "clicked" state should generate one "squeeze"
+    // event. Reset the input value to prevent it from continuously generating
+    // events.
+    this.primary_squeeze_clicked_ = false;
+
+    input_state.mojoFromInput = this.mojo_from_input_;
+
+    input_state.gamepad = this.gamepad_;
+
+    input_state.emulatedPosition = this.emulated_position_;
+
+    if (this.desc_dirty_) {
+      const input_desc = {};
+
+      switch (this.target_ray_mode_) {
+        case 'gaze':
+          input_desc.targetRayMode = vrMojom.XRTargetRayMode.GAZING;
+          break;
+        case 'tracked-pointer':
+          input_desc.targetRayMode = vrMojom.XRTargetRayMode.POINTING;
+          break;
+        case 'screen':
+          input_desc.targetRayMode = vrMojom.XRTargetRayMode.TAPPING;
+          break;
+        default:
+          throw new Error('Unhandled target ray mode ' + this.target_ray_mode_);
+      }
+
+      switch (this.handedness_) {
+        case 'left':
+          input_desc.handedness = vrMojom.XRHandedness.LEFT;
+          break;
+        case 'right':
+          input_desc.handedness = vrMojom.XRHandedness.RIGHT;
+          break;
+        default:
+          input_desc.handedness = vrMojom.XRHandedness.NONE;
+          break;
+      }
+
+      // Mojo requires us to send the pointerOrigin as relative to the grip
+      // space. If we don't have a grip space, we'll just assume that there
+      // is a grip at identity. This allows tests to simulate controllers that
+      // are really just a pointer with no tracked grip, though we will end up
+      // exposing that grip space.
+      let mojo_from_input = XRMathHelper.identity();
+      switch (this.target_ray_mode_) {
+        case 'gaze':
+        case 'screen':
+          // For gaze and screen space, we won't have a mojo_from_input; however
+          // the "input" position is just the viewer, so use mojo_from_viewer.
+          mojo_from_input = this.pairedDevice_._getMojoFromViewer();
+          break;
+        case 'tracked-pointer':
+          // If we have a tracked grip position (e.g. mojo_from_input), then use
+          // that. If we don't, then we'll just set the pointer offset directly,
+          // using identity as set above.
+          if (this.mojo_from_input_) {
+            mojo_from_input = this.mojo_from_input_.matrix;
+          }
+          break;
+        default:
+          throw new Error('Unhandled target ray mode ' + this.target_ray_mode_);
+      }
+
+      // To convert mojo_from_pointer to input_from_pointer, we need:
+      // input_from_pointer = input_from_mojo * mojo_from_pointer
+      // Since we store mojo_from_input, we need to invert it here before
+      // multiplying.
+      let input_from_mojo = XRMathHelper.inverse(mojo_from_input);
+      input_desc.inputFromPointer = {};
+      input_desc.inputFromPointer.matrix =
+        XRMathHelper.mul4x4(input_from_mojo, this.mojo_from_pointer_.matrix);
+
+      input_desc.profiles = this.profiles_;
+
+      input_state.description = input_desc;
+
+      this.desc_dirty_ = false;
+    }
+
+    // Pointer data for DOM Overlay, set by setOverlayPointerPosition()
+    if (this.overlay_pointer_position_) {
+      input_state.overlayPointerPosition = this.overlay_pointer_position_;
+      this.overlay_pointer_position_ = null;
+    }
+
+    return input_state;
+  }
+
+  _getEmptyGamepad() {
+    // Mojo complains if some of the properties on Gamepad are null, so set
+    // everything to reasonable defaults that tests can override.
+    const gamepad = {
+      connected: true,
+      id: [],
+      timestamp: 0n,
+      axes: [],
+      buttons: [],
+      touchEvents: [],
+      mapping: GamepadMapping.GamepadMappingStandard,
+      displayId: 0,
+    };
+
+    switch (this.handedness_) {
+      case 'left':
+      gamepad.hand = GamepadHand.GamepadHandLeft;
+      break;
+      case 'right':
+      gamepad.hand = GamepadHand.GamepadHandRight;
+      break;
+      default:
+      gamepad.hand = GamepadHand.GamepadHandNone;
+      break;
+    }
+
+    return gamepad;
+  }
+
+  _addGamepadButton(buttonState) {
+    if (buttonState == null) {
+      return;
+    }
+
+    const buttonIndex = this._getButtonIndex(buttonState.buttonType);
+    const axesStartIndex = this._getAxesStartIndex(buttonState.buttonType);
+
+    if (buttonIndex == -1) {
+      throw new Error("Unknown Button Type!");
+    }
+
+    this.gamepad_.buttons[buttonIndex] = {
+      pressed: buttonState.pressed,
+      touched: buttonState.touched,
+      value: buttonState.pressedValue
+    };
+
+    // Add x/y value if supported.
+    if (axesStartIndex != -1) {
+      this.gamepad_.axes[axesStartIndex] = (buttonState.xValue == null ? 0.0 : buttonSate.xValue);
+      this.gamepad_.axes[axesStartIndex + 1] = (buttonState.yValue == null ? 0.0 : buttonSate.yValue);
+    }
+  }
+
+  // General Helper methods
+  _getButtonIndex(buttonType) {
+    switch (buttonType) {
+      case 'grip':
+        return 1;
+      case 'touchpad':
+        return 2;
+      case 'thumbstick':
+        return 3;
+      case 'optional-button':
+        return 4;
+      case 'optional-thumbstick':
+        return 5;
+      default:
+        return -1;
+    }
+  }
+
+  _getAxesStartIndex(buttonType) {
+    switch (buttonType) {
+      case 'touchpad':
+        return 0;
+      case 'thumbstick':
+        return 2;
+      case 'optional-thumbstick':
+        return 4;
+      default:
+        return -1;
+    }
+  }
+
+  _getMojoFromInputSource(mojo_from_viewer) {
+    return this.mojo_from_pointer_.matrix;
+  }
+}
+
+// Mojo helper classes
+class FakeXRHitTestSourceController {
+  constructor(id) {
+    this.id_ = id;
+    this.deleted_ = false;
+  }
+
+  get deleted() {
+    return this.deleted_;
+  }
+
+  // Internal setter:
+  set deleted(value) {
+    this.deleted_ = value;
+  }
+}
+
+class MockXRPresentationProvider {
+  constructor() {
+    this.receiver_ = null;
+    this.submit_frame_count_ = 0;
+    this.missing_frame_count_ = 0;
+  }
+
+  _bindProvider() {
+    const provider = new vrMojom.XRPresentationProviderRemote();
+
+    if (this.receiver_) {
+      this.receiver_.$.close();
+    }
+    this.receiver_ = new vrMojom.XRPresentationProviderReceiver(this);
+    this.receiver_.$.bindHandle(provider.$.bindNewPipeAndPassReceiver().handle);
+    return provider;
+  }
+
+  _getClientReceiver() {
+    this.submitFrameClient_ = new vrMojom.XRPresentationClientRemote();
+    return this.submitFrameClient_.$.bindNewPipeAndPassReceiver();
+  }
+
+  // XRPresentationProvider mojo implementation
+  updateLayerBounds(frameId, leftBounds, rightBounds, sourceSize) {}
+
+  submitFrameMissing(frameId, mailboxHolder, timeWaited) {
+    this.missing_frame_count_++;
+  }
+
+  submitFrame(frameId, mailboxHolder, timeWaited) {
+    this.submit_frame_count_++;
+
+    // Trigger the submit completion callbacks here. WARNING: The
+    // Javascript-based mojo mocks are *not* re-entrant. It's OK to
+    // wait for these notifications on the next frame, but waiting
+    // within the current frame would never finish since the incoming
+    // calls would be queued until the current execution context finishes.
+    this.submitFrameClient_.onSubmitFrameTransferred(true);
+    this.submitFrameClient_.onSubmitFrameRendered();
+  }
+
+  submitFrameWithTextureHandle(frameId, texture, syncToken) {}
+
+  submitFrameDrawnIntoTexture(frameId, syncToken, timeWaited) {}
+
+  // Utility methods
+  _close() {
+    if (this.receiver_) {
+      this.receiver_.$.close();
+    }
+  }
+}
+
+// Export these into the global object as a side effect of importing this
+// module.
+self.ChromeXRTest = ChromeXRTest;
+self.MockRuntime = MockRuntime;
+self.MockVRService = MockVRService;
+self.SubscribeToHitTestResult = vrMojom.SubscribeToHitTestResult;
+
+navigator.xr.test = new ChromeXRTest();
diff --git a/testing/web-platform/tests/resources/chromium/webxr-test.js.headers b/testing/web-platform/tests/resources/chromium/webxr-test.js.headers
new file mode 100644
index 0000000000..6805c323df
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webxr-test.js.headers
@@ -0,0 +1 @@
+Content-Type: text/javascript; charset=utf-8