MD Settings: Ensure all search results are visible when going back.

chrome/browser/resources/settings/settings_main/settings_main.js

 // Copyright 2015 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.
 
 /**
  * @typedef {{about: boolean, basic: boolean, advanced: boolean}}
  */
 var MainPageVisibility;
 
 /**
@@ skipping 27 matching lines @@
      */
     hasExpandedSection_: Boolean,
 
     /** @private */
     overscroll_: {
       type: Number,
       observer: 'overscrollChanged_',
     },
 
     /**
-     * Controls which main pages are displayed via dom-ifs.
+     * Controls which main pages are displayed via dom-ifs, based on the current
+     * route and the Advanced toggle state.
      * @private {!MainPageVisibility}
      */
     showPages_: {
       type: Object,
       value: function() {
         return {about: false, basic: false, advanced: false};
       },
     },
 
     /**
@@ skipping 79 matching lines @@
 
   /**
    * @return {boolean}
    * @private
    */
   showAdvancedToggle_: function() {
     return !this.inSearchMode_ && this.showPages_.basic &&
         !this.hasExpandedSection_;
   },
 
+  /**
+   * @return {boolean} Whether to show the basic page, taking into account both
+   *     routing and search state.
+   * @private
+   */
+  showBasicPage_: function() {
+    return this.showPages_.basic || this.inSearchMode_;
+  },
+
+  /**
+   * @return {boolean} Whether to show the advanced page, taking into account
+   *     both routing and search state.
+   * @private
+   */
+  showAdvancedPage_: function() {
+    return this.showPages_.advanced || this.inSearchMode_;
+  },
+
+  /** @param {!settings.Route} newRoute */
   currentRouteChanged: function(newRoute) {
     // When the route changes from a sub-page to the main page, immediately
     // update hasExpandedSection_ to unhide the other sections.
     if (!newRoute.isSubpage())
       this.hasExpandedSection_ = false;
 
     if (settings.Route.ADVANCED.contains(newRoute))
       this.advancedToggleExpanded_ = true;
 
     this.updatePagesShown_();
@@ skipping 95 matching lines @@
   ensureInDefaultSearchPage_: function() {
     if (settings.getCurrentRoute() != settings.Route.BASIC)
       settings.navigateTo(settings.Route.BASIC);
   },
 
   /**
    * @param {string} query
    * @return {!Promise} A promise indicating that searching finished.
    */
   searchContents: function(query) {
+    // Trigger rendering of the basic and advanced pages and search once ready.
     this.inSearchMode_ = true;

[dpapad, 2016/09/20 22:32:15]

Using inSearchMode_ to force the basic and advanced pages to be force-shown
seems much more robust, than messing with the showPages_ variable itself, which
is modified by routing as well as external events (see onSubpageExpand_ callback
for example).

     this.ensureInDefaultSearchPage_();
     this.toolbarSpinnerActive = true;
 
-    // Trigger rendering of the basic and advanced pages and search once ready.
-    this.showPages_ = {about: false, basic: true, advanced: true};
-
     return new Promise(function(resolve, reject) {
       setTimeout(function() {
         var whenSearchDone = settings.getSearchManager().search(
             query, assert(this.getPage_(settings.Route.BASIC)));
         assert(
             whenSearchDone ===
                 settings.getSearchManager().search(
                     query, assert(this.getPage_(settings.Route.ADVANCED))));
 
         whenSearchDone.then(function(request) {
           resolve();
           if (!request.finished) {
             // Nothing to do here. A previous search request was canceled
             // because a new search request was issued before the first one
             // completed.
             return;
           }
 
           this.toolbarSpinnerActive = false;
           this.inSearchMode_ = !request.isSame('');
           this.showNoResultsFound_ =
               this.inSearchMode_ && !request.didFindMatches();
-
-          if (!this.inSearchMode_) {
-            // Restore the "advanced" page visibility as it was before search
-            // was initiated.
-            this.showPages_ = {
-              about: false, basic: true, advanced: this.advancedToggleExpanded_,
-            };
-          }
         }.bind(this));
       }.bind(this), 0);
     }.bind(this));
   },
 
   /**
    * @param {(boolean|undefined)} visibility
    * @return {boolean} True unless visibility is false.
    * @private
    */
   showAdvancedSettings_: function(visibility) {
     return visibility !== false;
   },
 });