MD Settings: Add mechanism to restore focus after subpage exiting.

chrome/test/data/webui/settings/cr_settings_interactive_ui_tests.js

Index: chrome/test/data/webui/settings/cr_settings_interactive_ui_tests.js
diff --git a/chrome/test/data/webui/settings/cr_settings_interactive_ui_tests.js b/chrome/test/data/webui/settings/cr_settings_interactive_ui_tests.js
index bc3659e85ae8b41d22b50feef356f69a3811c299..9f4b7e31d419cca07d0e81eaba275a239f12a112 100644
--- a/chrome/test/data/webui/settings/cr_settings_interactive_ui_tests.js
+++ b/chrome/test/data/webui/settings/cr_settings_interactive_ui_tests.js
@@ -64,3 +64,26 @@ CrSettingsFocusRowBehavior.prototype = {
 TEST_F('CrSettingsFocusRowBehavior', 'FocusTest', function() {
   mocha.run();
 });
+
+
+/**
+ * @constructor
+ * @extends {CrSettingsInteractiveUITest}
+ */
+function CrSettingsAnimatedPagesTest() {}
+
+CrSettingsAnimatedPagesTest.prototype = {
+  __proto__: CrSettingsInteractiveUITest.prototype,
+
+  /** @override */
+  browsePreload:
+      'chrome://md-settings/settings_page/settings_animated_pages.html',
+
+  extraLibraries: CrSettingsInteractiveUITest.prototype.extraLibraries.concat([
+    'settings_animated_pages_test.js',
+  ]),
+};
+
+TEST_F('CrSettingsAnimatedPagesTest', 'All', function() {
+  mocha.run()
+});