Added Web Share (navigator.share) experimental web API (stub).

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

+'use strict';
+
+let mockShareService = loadMojoModules(
+    'mockShareService',
+    ['mojo/public/js/router',
+     'third_party/WebKit/public/platform/modules/webshare/webshare.mojom',
+    ]).then(mojo => {
+  let [router, webshare] = mojo.modules;
+
+  class MockShareService extends webshare.ShareService.stubClass {
+    constructor(serviceRegistry) {
+      super();
+      serviceRegistry.addServiceOverrideForTesting(
+          webshare.ShareService.name,
+          handle => this.connect_(handle));
+    }
+
+    // Returns a Promise that gets rejected if the test should fail.
+    init_() {
+      // sequence of [expectedTitle, expectedText, result].
+      this.shareResultQueue_ = [];
+
+      return new Promise((resolve, reject) => {this.reject_ = reject});
+    }
+
+    connect_(handle) {
+      this.router_ = new router.Router(handle);
+      this.router_.setIncomingReceiver(this);
+    }
+
+    share(title, text) {
+      let callback = null;
+      let result = new Promise(resolve => {callback = resolve;});
+
+      if (!this.shareResultQueue_.length) {
+        this.reject_('Unexpected call to mojo share method');
+        return result;
+      }
+
+      let expectedTitle, expectedText, error;
+      [expectedTitle, expectedText, error] = this.shareResultQueue_.shift();
+      try {
+        assert_equals(title, expectedTitle);
+        assert_equals(text, expectedText);
+      } catch (e) {
+        this.reject_(e);
+        return result;
+      }
+      callback({error: error});
+
+      return result;
+    }
+
+    pushShareResult(expectedTitle, expectedText, result) {
+      this.shareResultQueue_.push([expectedTitle, expectedText, result]);
+    }
+  }
+  return new MockShareService(mojo.frameServiceRegistry);
+});
+
+function share_test(func, name, properties) {
+  promise_test(t => mockShareService.then(mock => {
+    let mockPromise = mock.init_();
+    return Promise.race([func(t, mock), mockPromise]);
+  }), name, properties);
+}