MD Settings: Restore focus after exiting Content settings sub-subpages.

chrome/browser/resources/settings/site_settings_page/site_settings_page.js

Index: chrome/browser/resources/settings/site_settings_page/site_settings_page.js
diff --git a/chrome/browser/resources/settings/site_settings_page/site_settings_page.js b/chrome/browser/resources/settings/site_settings_page/site_settings_page.js
index b1e40a46a8da057ca75e69b093d3d8abc6b6383a..b8a25e91039f44485ada0f384a4961a5c65a2335 100644
--- a/chrome/browser/resources/settings/site_settings_page/site_settings_page.js
+++ b/chrome/browser/resources/settings/site_settings_page/site_settings_page.js
@@ -49,6 +49,54 @@ Polymer({
       }
     },
 
+    /** @type {!Map<string, string>} */

[Dan Beam, 2017/04/12 02:32:02]

@override maybe?

[dpapad, 2017/04/12 03:22:52]

Tried @override and compiler seems to be happy either way, but semantically I
don't think override is appropriate. This is not inherited from any superclass
(or behavior), it is simply passed from the outside.

+    focusConfig: {
+      type: Object,
+      observer: 'focusConfigChanged_',
+    },
+  },
+
+  /**
+   * @param {!Map<string, string>} current

[Dan Beam, 2017/04/12 02:32:02]

nit: newConfig, oldConfig

[dpapad, 2017/04/12 03:22:52]

Done.

+   * @param {?Map<string, string>} previous
+   * @private
+   */
+  focusConfigChanged_: function(current, previous) {
+    if (previous != undefined) {
+      // Should never happen since focusConfig is set only once on the parent.
+      return;
+    }

[Dan Beam, 2017/04/12 02:32:02]

assert(!oldConfig);

[dpapad, 2017/04/12 03:22:52]

Done.

+
+    // Populate the |focusConfig| map of the parent <settings-animated-pages>
+    // element, with additional entries that correspond to subpage trigger
+    // elements residing in this element's Shadow DOM.

[dpapad, 2017/04/12 02:05:28]

Populating this.focusConfig only after it is set to an initial value has two
benefits
1) It ensures that there are no race conditions (always executes after the
parent sets the initial value).
2) In site_settings_page_browsertest.js tests, where a settings-animated-pages
is created on its own and has no parent, this code never executes on purpose.

+    var R = settings.Route;
+    [
+      [R.SITE_SETTINGS_COOKIES, 'cookies'],
+      [R.SITE_SETTINGS_LOCATION, 'location'],
+      [R.SITE_SETTINGS_CAMERA, 'camera'],
+      [R.SITE_SETTINGS_MICROPHONE, 'microphone'],
+      [R.SITE_SETTINGS_NOTIFICATIONS, 'notifications'],
+      [R.SITE_SETTINGS_JAVASCRIPT,'javascript'],
+      [R.SITE_SETTINGS_FLASH,'flash'],
+      [R.SITE_SETTINGS_IMAGES,'images'],
+      [R.SITE_SETTINGS_POPUPS,'popups'],
+      [R.SITE_SETTINGS_BACKGROUND_SYNC,'background-sync'],
+      [R.SITE_SETTINGS_AUTOMATIC_DOWNLOADS,'automatic-downloads'],
+      [R.SITE_SETTINGS_UNSANDBOXED_PLUGINS,'unsandboxed-plugins'],
+      [R.SITE_SETTINGS_HANDLERS,'protocol-handlers'],
+      [R.SITE_SETTINGS_MIDI_DEVICES,'midi-devices'],
+      [R.SITE_SETTINGS_SUBRESOURCE_FILTER,'subresource-filter'],
+      [R.SITE_SETTINGS_ZOOM_LEVELS,'zoom-levels'],
+      [R.SITE_SETTINGS_USB_DEVICES,'usb-devices'],
+      [R.SITE_SETTINGS_PDF_DOCUMENTS,'pdf-documents'],
+      [R.SITE_SETTINGS_PROTECTED_CONTENT,'protected-content'],
+    ].forEach(function(pair) {
+      var route = pair[0];
+      var id = pair[1];
+      this.focusConfig.set(
+          route.path, '* /deep/ #' + id + ' .subpage-arrow');
+    }.bind(this));
   },
 
   /** @override */