bluetooth: Add device details page with basic properties to internals page.

ui/webui/resources/js/cr/ui/page_manager/page_manager.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('cr.ui.pageManager', function() {
   /**
    * PageManager contains a list of root Page and overlay Page objects and
    * handles "navigation" by showing and hiding these pages and overlays. On
    * initial load, PageManager can use the path to open the correct hierarchy
    * of pages and overlay(s). Handlers for user events, like pressing buttons,
@@ skipping 65 matching lines @@
     /**
      * Registers new page.
      * @param {!cr.ui.pageManager.Page} page Page to register.
      */
     register: function(page) {
       this.registeredPages[page.name.toLowerCase()] = page;
       page.initializePage();
     },
 
     /**
+     * Unregisters an existing page.
+     * @param {!cr.ui.pageManager.Page} page Page to unregister.
+     */
+    unregister: function(page) {
+      delete this.registeredPages[page.name.toLowerCase()];

[dpapad, 2017/01/12 22:53:21]

Is it necessary to unregister a page? I am wondering if unregistering a page can
cause an obsolete entry to remain in history. See lines 201-202.

[mbrunson, 2017/01/12 23:09:19]

Unregistering a page can create an obsolete entry but I think it's up to
observers to update and handle the history appropriately. PageManager doesn't
set window.history or window.location directly. Because of this, I created a
PageObserver that updates the history stack by changing location.hash after
receiving the new path from PageManager[1]. An event handler determines if this
change is valid and shows the page[2]. If it's invalid, the page is not updated.

[1] (Line 49)
https://codereview.chromium.org/2576603002/diff/240001/chrome/browser/resourc...
[2] (Line 256)
https://codereview.chromium.org/2576603002/diff/240001/chrome/browser/resourc...

+    },
+
+    /**
      * Registers a new Overlay page.
      * @param {!cr.ui.pageManager.Page} overlay Overlay to register.
      * @param {cr.ui.pageManager.Page} parentPage Associated parent page for
      *     this overlay.
      * @param {Array} associatedControls Array of control elements associated
      *     with this page.
      */
     registerOverlay: function(overlay, parentPage, associatedControls) {
       this.registeredOverlayPages[overlay.name.toLowerCase()] = overlay;
       overlay.parentPage = parentPage;
@@ skipping 654 matching lines @@
      * Called when a page is navigated to.
      * @param {string} path The path of the page being visited.
      * @param {boolean} replace If true, allow no history events to be created.
      */
     updateHistory: function(path, replace) {},
   };
 
   // Export
   return {PageManager: PageManager};
 });