Adding upstream version 110.0.1.upstream/110.0.1upstream

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

1 files changed, 2125 insertions, 0 deletions

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..452cdfa5e3
--- /dev/null
+++ b/testing/web-platform/tests/resources/chromium/webxr-test.js
@@ -0,0 +1,2125 @@
+import * as vrMojom from '/gen/device/vr/public/mojom/vr_service.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': vrMojom.XRSessionFeature.REF_SPACE_VIEWER,
+    'local': vrMojom.XRSessionFeature.REF_SPACE_LOCAL,
+    'local-floor': vrMojom.XRSessionFeature.REF_SPACE_LOCAL_FLOOR,
+    'bounded-floor': vrMojom.XRSessionFeature.REF_SPACE_BOUNDED_FLOOR,
+    'unbounded': vrMojom.XRSessionFeature.REF_SPACE_UNBOUNDED,
+    'hit-test': vrMojom.XRSessionFeature.HIT_TEST,
+    'dom-overlay': vrMojom.XRSessionFeature.DOM_OVERLAY,
+    'light-estimation': vrMojom.XRSessionFeature.LIGHT_ESTIMATION,
+    'anchors': vrMojom.XRSessionFeature.ANCHORS,
+    'depth-sensing': vrMojom.XRSessionFeature.DEPTH,
+    'secondary-views': vrMojom.XRSessionFeature.SECONDARY_VIEWS,
+    'camera-access': vrMojom.XRSessionFeature.CAMERA_ACCESS,
+  };
+
+  static _sessionModeToMojoMap = {
+    "inline": vrMojom.XRSessionMode.kInline,
+    "immersive-vr": vrMojom.XRSessionMode.kImmersiveVr,
+    "immersive-ar": vrMojom.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(vrMojom.XRSessionMode.kImmersiveAr)) {
+        return vrMojom.XREnvironmentBlendMode.kAdditive;
+      } else if (this.supportedModes_.includes(
+            vrMojom.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 vrMojom.XRSessionFeature.INVALID;
+      }
+    }
+
+    this.supportedFeatures_ = [];
+
+    for (let i = 0; i < supportedFeatures.length; i++) {
+      const feature = convertFeatureToMojom(supportedFeatures[i]);
+      if (feature !== vrMojom.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(vrMojom.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 == vrMojom.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(vrMojom.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(vrMojom.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(vrMojom.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(vrMojom.XRSessionFeature.DEPTH)
+    || options.optionalFeatures.includes(vrMojom.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(vrMojom.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(vrMojom.XRSessionMode.kImmersiveAr)) {
+      return;
+    }
+
+    if (!this.enabledFeatures_.includes(vrMojom.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(vrMojom.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: [],
+      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();