Print Preview: Fix compile errors in settings/ directory

chrome/browser/resources/print_preview/settings/advanced_settings/advanced_settings.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('print_preview', function() {
   'use strict';
 
   /**
    * Modal dialog for print destination's advanced settings.
    * @param {!print_preview.PrintTicketStore} printTicketStore Contains the
@@ skipping 19 matching lines @@
     /** @private {!print_preview.SearchBox} */
     this.searchBox_ = new print_preview.SearchBox(
         loadTimeData.getString('advancedSettingsSearchBoxPlaceholder'));
     this.addChild(this.searchBox_);
 
     /** @private {print_preview.Destination} */
     this.destination_ = null;
 
     /** @private {!Array<!print_preview.AdvancedSettingsItem>} */
     this.items_ = [];
-  };
+  }
 
   /**
    * CSS classes used by the component.
    * @enum {string}
    * @private
    */
   AdvancedSettings.Classes_ = {
     EXTRA_PADDING: 'advanced-settings-item-extra-padding'
   };
 
@@ skipping 12 matching lines @@
                                   this.destination_.displayName);
       this.setIsVisible(true);
       this.renderSettings_();
     },
 
     /** @override */
     enterDocument: function() {
       print_preview.Overlay.prototype.enterDocument.call(this);
 
       this.tracker.add(
-          this.getChildElement('.button-strip .cancel-button'),
+          assert(this.getChildElement('.button-strip .cancel-button')),

[dpapad, 2017/05/04 01:20:04]

Follow up from previous comment: if we make getChildElement() return
!HTMLElement, there would be no need to assert here, but that requires ensuring
that there are no valid use cases for having getChildElement() return null.

[rbpotter, 2017/05/04 01:43:07]

Acknowledged - will investigate getChildElement and upload a follow up
CL if it is possible to make it return !HTMLElement.

           'click',
           this.cancel.bind(this));
 
       this.tracker.add(
-          this.getChildElement('.button-strip .done-button'),
+          assert(this.getChildElement('.button-strip .done-button')),
           'click',
           this.onApplySettings_.bind(this));
 
       this.tracker.add(
-          this.searchBox_,
+          assert(this.searchBox_),
           print_preview.SearchBox.EventType.SEARCH,
           this.onSearch_.bind(this));
     },
 
     /** @override */
     decorateInternal: function() {
-      this.searchBox_.render(this.getChildElement('.search-box-area'));
+      this.searchBox_.render(assert(this.getChildElement('.search-box-area')));
     },
 
     /** @override */
     onSetVisibleInternal: function(isVisible) {
       if (isVisible) {
         this.searchBox_.focus();
         this.metrics_.record(print_preview.Metrics.PrintSettingsUiBucket.
             ADVANCED_SETTINGS_DIALOG_SHOWN);
       } else {
         this.resetSearch_();
@@ skipping 23 matching lines @@
       var elStyle = window.getComputedStyle(this.getElement());
       return this.getElement().offsetHeight -
           parseInt(elStyle.getPropertyValue('padding-top'), 10) -
           parseInt(elStyle.getPropertyValue('padding-bottom'), 10) -
           this.getChildElement('.settings-area').offsetTop -
           this.getChildElement('.action-area').offsetHeight;
     },
 
     /**
      * Filters displayed settings with the given query.
-     * @param {?string} query Query to filter settings by.
+     * @param {?RegExp} query Query to filter settings by.
      * @private
      */
     filterLists_: function(query) {
       var atLeastOneMatch = false;
       var lastVisibleItemWithBubble = null;
       this.items_.forEach(function(item) {
         item.updateSearchQuery(query);
         if (getIsVisible(item.getElement()))
           atLeastOneMatch = true;
         if (item.searchBubbleShown)
           lastVisibleItemWithBubble = item;
       });
       setIsVisible(
-          this.getChildElement('.no-settings-match-hint'), !atLeastOneMatch);
+          assert(this.getChildElement('.no-settings-match-hint')),
+          !atLeastOneMatch);
       setIsVisible(
-          this.getChildElement('.' + AdvancedSettings.Classes_.EXTRA_PADDING),
+          assert(this.getChildElement(
+              '.' + AdvancedSettings.Classes_.EXTRA_PADDING)),
           !!lastVisibleItemWithBubble);
     },
 
     /**
      * Resets the filter query.
      * @private
      */
     resetSearch_: function() {
       this.searchBox_.setQuery(null);
       this.filterLists_(null);
@@ skipping 19 matching lines @@
       if (!vendorCapabilities)
         return;
 
       var availableHeight = this.getAvailableContentHeight_();
       var containerEl = this.getChildElement('.settings-area');
       containerEl.style.maxHeight = availableHeight + 'px';
       var settingsEl = this.getChildElement('.settings');
 
       vendorCapabilities.forEach(function(capability) {
         var item = new print_preview.AdvancedSettingsItem(
-            this.eventTarget_, this.printTicketStore_, capability);
+            this.printTicketStore_, capability);
         this.addChild(item);
-        item.render(settingsEl);
+        item.render(assert(settingsEl));
         this.items_.push(item);
       }.bind(this));
 
       if (this.items_.length <= 1) {
-        setIsVisible(this.getChildElement('.search-box-area'), false);
+        setIsVisible(assert(this.getChildElement('.search-box-area')), false);

[dpapad, 2017/05/04 01:20:04]

Nit: Assertions are not free. Perhaps use a local var to avoid asserting twice

var searchBoxArea = assert(this.getChildElement('.search-box-area'));
...

[rbpotter, 2017/05/04 01:43:06]

Done.

       } else {
-        setIsVisible(this.getChildElement('.search-box-area'), true);
+        setIsVisible(assert(this.getChildElement('.search-box-area')), true);
         this.searchBox_.focus();
       }
 
       extraPadding = document.createElement('div');
       extraPadding.classList.add(AdvancedSettings.Classes_.EXTRA_PADDING);
       extraPadding.hidden = true;
       settingsEl.appendChild(extraPadding);
     },
 
     /**
@@ skipping 21 matching lines @@
 
       this.printTicketStore_.vendorItems.updateValue(values);
     }
   };
 
   // Export
   return {
     AdvancedSettings: AdvancedSettings
   };
 });