[Extensions] Add extension name to page title for details page

Change page title for the extensions details page in chrome://extensions
to Extensions - <extension name>

Bug: 867053
Change-Id: I3383ff4f3f0105ca10cbd8609ab5a311e03bf4d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1669909Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Kelvin Jiang <kelvinjiang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#671738}

chrome/browser/resources/extensions/manager.js

@@ -521,6 +521,9 @@ cr.define('extensions', function() {
         });
       }
 
+      document.title = toPage == Page.DETAILS ?
+          `${loadTimeData.getString('title')} - ${this.detailViewItem_.name}` :
+          loadTimeData.getString('title');
       this.currentPage_ = newPage;
     },
 

chrome/test/data/webui/extensions/cr_extensions_browsertest.js

@@ -577,6 +577,12 @@ TEST_F(
       this.runMochaTest(extension_manager_tests.TestNames.ChangePages);
     });
 
+TEST_F(
+    'CrExtensionsManagerTestWithMultipleExtensionTypesInstalled',
+    'PageTitleUpdate', function() {
+      this.runMochaTest(extension_manager_tests.TestNames.PageTitleUpdate);
+    });
+
 // eslint-disable-next-line no-var
 var CrExtensionsManagerTestWithIdQueryParam =
     class extends CrExtensionsBrowserTestWithInstalledExtension {

chrome/test/data/webui/extensions/manager_test.js

@@ -9,6 +9,7 @@ cr.define('extension_manager_tests', function() {
     ChangePages: 'change pages',
     ItemListVisibility: 'item list visibility',
     SplitItems: 'split items',
+    PageTitleUpdate: 'updates the title based on current route',
     UrlNavigationToDetails: 'url navigation to details',
     UrlNavigationToActivityLogFail:
         'url navigation to activity log without flag set',
@@ -110,6 +111,23 @@ cr.define('extension_manager_tests', function() {
       assertViewActive('extensions-item-list');
     });
 
+    test(assert(TestNames.PageTitleUpdate), function() {
+      expectEquals('Extensions', document.title);
+
+      // Open details view with a valid ID.
+      extensions.navigation.navigateTo({
+        page: Page.DETAILS,
+        extensionId: 'ldnnhddmnhbkjipkidpdiheffobcpfmf'
+      });
+      Polymer.dom.flush();
+      expectEquals('Extensions - My extension 1', document.title);
+
+      // Navigate back to the list view and check the page title.
+      extensions.navigation.navigateTo({page: Page.LIST});
+      Polymer.dom.flush();
+      expectEquals('Extensions', document.title);
+    });
+
     test(assert(TestNames.UrlNavigationToDetails), function() {
       assertViewActive('extensions-detail-view');
       const detailsView = manager.$$('extensions-detail-view');