Web Share: Refactor Mojo interface to now return an enum error.

third_party/WebKit/LayoutTests/webshare/resources/mock-share-service.js

 'use strict';
 
 let mockShareService = loadMojoModules(
     'mockShareService',
     ['mojo/public/js/bindings',
      'third_party/WebKit/public/platform/modules/webshare/webshare.mojom',
     ]).then(mojo => {
   let [bindings, webshare] = mojo.modules;
 
   class MockShareService {
     constructor(interfaceProvider) {
+      this.webshare_ = webshare;
       this.bindingSet_ = new bindings.BindingSet(webshare.ShareService);
 
       interfaceProvider.addInterfaceOverrideForTesting(
           webshare.ShareService.name,
           handle => this.bindingSet_.addBinding(this, handle));
     }
 
     // Returns a Promise that gets rejected if the test should fail.
     init_() {
       // sequence of [expectedTitle, expectedText, result].
@@ skipping 30 matching lines @@
       this.shareResultQueue_.push(
           [expectedTitle, expectedText, expectedUrl, result]);
     }
   }
   return new MockShareService(mojo.frameInterfaces);
 });
 
 function share_test(func, name, properties) {
   promise_test(t => mockShareService.then(mock => {
     let mockPromise = mock.init_();
-    return Promise.race([func(t, mock), mockPromise]);
+    return Promise.race([func(t, mock.webshare_, mock), mockPromise]);
   }), name, properties);
 }
 
 // Copied from resources/bluetooth/bluetooth-helpers.js.
 function callWithKeyDown(functionCalledOnKeyPress) {
   return new Promise(resolve => {
     function onKeyPress() {
       document.removeEventListener('keypress', onKeyPress, false);
       resolve(functionCalledOnKeyPress());
     }
     document.addEventListener('keypress', onKeyPress, false);
 
     eventSender.keyDown(' ', []);
   });
 }