MD Settings: use theme homepage URLs when set

chrome/browser/resources/settings/appearance_page/appearance_page.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.
 
 /**
  * 'settings-appearance-page' is the settings page containing appearance
  * settings.
  *
  * Example:
  *
@@ skipping 83 matching lines @@
     /** @private */
     themeSublabel_: String,
 
     /**
      * Dictionary defining page visibility.
      * @type {!AppearancePageVisibility}
      */
     pageVisibility: Object,
   },
 
+  /** @private {string} */
+  themeUrl_: '',
+
   observers: [
     'themeChanged_(prefs.extensions.theme.id.value, useSystemTheme_)',
 
 <if expr="is_linux and not chromeos">
     // NOTE: this pref only exists on Linux.
     'useSystemThemePrefChanged_(prefs.extensions.theme.use_system.value)',
 </if>
 
     'zoomLevelChanged_(defaultZoomLevel_.value)',
   ],
@@ skipping 22 matching lines @@
       return this.i18n('homePageNtp');
     return homepage || this.i18n('exampleDotCom');
   },
 
   /** @private */
   onCustomizeFontsTap_: function() {
     settings.navigateTo(settings.Route.FONTS);
   },
 
   /** @private */
-  openThemesGallery_: function() {
-    // TODO(dbeam): open the theme detail page when a custom theme is installed
-    // (or otherwise handle the [//] open in new icon in a better way).
-    window.open(loadTimeData.getString('themesGalleryUrl'));
+  onThemesTap_: function() {
+    window.open(this.themeUrl_ || loadTimeData.getString('themesGalleryUrl'));
   },
 
 <if expr="chromeos">
   /**
    * ChromeOS only.
    * @private
    */
   openWallpaperManager_: function() {
     this.browserProxy_.openWallpaperManager();
   },
@@ skipping 40 matching lines @@
 </if>
 
   /**
    * @param {string} themeId
    * @param {boolean} useSystemTheme
    * @private
    */
   themeChanged_: function(themeId, useSystemTheme) {
     if (themeId) {
       assert(!useSystemTheme);
+
       this.browserProxy_.getThemeInfo(themeId).then(function(info) {
         this.themeSublabel_ = info.name;
       }.bind(this));
+
+      this.themeUrl_ = `https://chrome.google.com/webstore/detail/${themeId}`;
       return;
     }
 
     var i18nId;
 <if expr="is_linux and not chromeos">
     i18nId = useSystemTheme ? 'systemTheme' : 'classicTheme';
 </if>
 <if expr="not is_linux or chromeos">
     i18nId = 'chooseFromWebStore';
 </if>
     this.themeSublabel_ = this.i18n(i18nId);
+    this.themeUrl_ = '';
   },
 
   /**
    * @param {number} percent The integer percentage of the page zoom.
    * @private
    */
   zoomPrefChanged_: function(percent) {
     this.set('defaultZoomLevel_.value', percent);
   },
 
@@ skipping 10 matching lines @@
 
   /**
    * @param {boolean} bookmarksBarVisible if bookmarks bar option is visible.
    * @return {string} 'first' if the argument is false or empty otherwise.
    * @private
    */
   getFirst_: function(bookmarksBarVisible) {
     return !bookmarksBarVisible ? 'first' : '';
   }
 });