[MD Extensions] Update subpages when the backing extension data changes

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

Index: chrome/test/data/webui/extensions/cr_extensions_browsertest.js
diff --git a/chrome/test/data/webui/extensions/cr_extensions_browsertest.js b/chrome/test/data/webui/extensions/cr_extensions_browsertest.js
index eed6c5c79dc2f15678967ba6ccd5ae767f16c8e1..06a8fe6b16b1104c79de5612354dcf43a20dff1a 100644
--- a/chrome/test/data/webui/extensions/cr_extensions_browsertest.js
+++ b/chrome/test/data/webui/extensions/cr_extensions_browsertest.js
@@ -239,6 +239,12 @@ TEST_F('CrExtensionsBrowserTestWithIdQueryParam',
       assert(extension_manager_tests.TestNames.UrlNavigationToDetails)).run();
 });
 
+TEST_F('CrExtensionsBrowserTest', 'ExtensionManagerUpdateItemDataTest',
+       function() {
+  extension_manager_tests.registerTests();
+  mocha.grep(assert(extension_manager_tests.TestNames.UpdateItemData)).run();
+});
+
 ////////////////////////////////////////////////////////////////////////////////
 // Extension Keyboard Shortcuts Tests