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

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

Index: third_party/WebKit/LayoutTests/webshare/resources/mock-share-service.js
diff --git a/third_party/WebKit/LayoutTests/webshare/resources/mock-share-service.js b/third_party/WebKit/LayoutTests/webshare/resources/mock-share-service.js
index 0e04983b5d29049b8d1b4cfec952d50d3a6102be..246305875376c2612ce3efa34a866915fa5a5841 100644
--- a/third_party/WebKit/LayoutTests/webshare/resources/mock-share-service.js
+++ b/third_party/WebKit/LayoutTests/webshare/resources/mock-share-service.js
@@ -9,6 +9,7 @@ let mockShareService = loadMojoModules(
 
   class MockShareService {
     constructor(interfaceProvider) {
+      this.webshare_ = webshare;
       this.bindingSet_ = new bindings.BindingSet(webshare.ShareService);
 
       interfaceProvider.addInterfaceOverrideForTesting(
@@ -59,7 +60,7 @@ let mockShareService = loadMojoModules(
 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);
 }