[Presentation API] Adds DOMString[] constructor to PresentationRequest.

third_party/WebKit/LayoutTests/presentation/resources/presentation-service-mock.js

 /*
  * Mock implementation of mojo PresentationService.
  */
 
 "use strict";
 
 let presentationServiceMock = loadMojoModules(
     'presentationServiceMock',
     [
       'third_party/WebKit/public/platform/modules/presentation/presentation.mojom',
@@ skipping 22 matching lines @@
         joinSession(urls) {
           return Promise.resolve({
               sessionInfo: { url: urls[0], id: 'fakeSessionId' },
               error: null,
           });
         }
       }
 
       return new PresentationServiceMock(mojo.frameInterfaces);
     });
+
+function waitForClick(callback, button) {
+  button.addEventListener('click', callback, { once: true });
+
+  if (!('eventSender' in window))
+    return;
+
+  var boundingRect = button.getBoundingClientRect();
+  var x = boundingRect.left + boundingRect.width / 2;
+  var y = boundingRect.top + boundingRect.height / 2;
+
+  eventSender.mouseMoveTo(x, y);
+  eventSender.mouseDown();
+  eventSender.mouseUp();
+}