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

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

Index: third_party/WebKit/LayoutTests/presentation/resources/presentation-service-mock.js
diff --git a/third_party/WebKit/LayoutTests/presentation/resources/presentation-service-mock.js b/third_party/WebKit/LayoutTests/presentation/resources/presentation-service-mock.js
index 790bba54640068ec5d79729cf1d15bbfcbd931b9..3db3d1ea3ca4bddcb83bb9f1701627cd94f5f5a6 100644
--- a/third_party/WebKit/LayoutTests/presentation/resources/presentation-service-mock.js
+++ b/third_party/WebKit/LayoutTests/presentation/resources/presentation-service-mock.js
@@ -40,3 +40,18 @@ let presentationServiceMock = loadMojoModules(
 
       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();
+}