core: OSS TensorBoard page title should be TensorBoard (#5190)

* core: OSS TensorBoard page title should be `TensorBoard`

* set OSS default experiment name to be ''

  Remove the explicit definition and check for OSS brand name, this will
  make it easy to support custom page titles in OSS in the future (if
  desired).

tensorboard/webapp/core/views/page_title_test.ts

@@ -187,3 +187,47 @@ describe('page title test with custom brand names', () => {
     expect(spy).toHaveBeenCalledWith('TensorBoard.corp');
   });
 });
+
+describe('page title test for OSS TensorBoard', () => {
+  let store: MockStore<State>;
+
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [PageTitleModule],
+      declarations: [TestingComponent],
+      providers: [
+        provideMockStore(),
+        {
+          provide: TB_BRAND_NAME,
+          useValue: 'TensorBoard',
+        },
+      ],
+      schemas: [NO_ERRORS_SCHEMA],
+    }).compileComponents();
+
+    store = TestBed.inject<Store<State>>(Store) as MockStore<State>;
+    store.overrideSelector(getRouteKind, RouteKind.EXPERIMENTS);
+    store.overrideSelector(getExperimentIdsFromRoute, []);
+    store.overrideSelector(getExperiment, null);
+    store.overrideSelector(getEnvironment, {
+      data_location: 'my-location',
+      window_title: '',
+    });
+  });
+
+  it('uses `TensorBoard` for experiment page title', () => {
+    const spy = spyOn(TEST_ONLY.utils, 'setDocumentTitle');
+    store.overrideSelector(getRouteKind, RouteKind.EXPERIMENT);
+    store.overrideSelector(getExperimentIdsFromRoute, ['defaultExperimentId']);
+    store.overrideSelector(
+      getExperiment,
+      buildExperiment({
+        name: '', // OSS default experiment name is ''
+      })
+    );
+    const fixture = TestBed.createComponent(TestingComponent);
+    fixture.detectChanges();
+
+    expect(spy).toHaveBeenCalledWith('TensorBoard');
+  });
+});

tensorboard/webapp/experiments/store/experiments_reducers.ts

@@ -25,7 +25,7 @@ import {ExperimentsDataState, ExperimentsState} from './experiments_types';
 
 const defaultExperiment = {
   id: DEFAULT_EXPERIMENT_ID,
-  name: 'Default experiment',
+  name: '',
   start_time: 0,
 };