message: MINOR: Fix BoundsGeneratorTest.
  Add dummy performance object, used in CameraMovementDetector.
diff: @@ -56,6 +56,7 @@ describe("BoundsGenerator", function() {
  theGlobal.requestAnimationFrame = (callback: (time: DOMHighResTimeStamp) => void) => {
  setTimeout(callback, 0);
  };
  + theGlobal.performance = { now: Date.now };
  }
  addEventListenerSpy = sinon.stub();
  removeEventListenerSpy = sinon.stub();
  