Flesh out the location-page class to make it more general.

chrome/browser/resources/settings/location_page/location_page.js

Index: chrome/browser/resources/settings/location_page/location_page.js
diff --git a/chrome/browser/resources/settings/location_page/location_page.js b/chrome/browser/resources/settings/location_page/location_page.js
index 1d8201bb641ed66a583086969914c07b7f65bd5d..85ff565e135ea5928b9d8b9252e1dec8d99b2b8a 100644
--- a/chrome/browser/resources/settings/location_page/location_page.js
+++ b/chrome/browser/resources/settings/location_page/location_page.js
@@ -16,6 +16,7 @@
  * @element cr-settings-location-page
  */
 Polymer({
+  /* TODO(finnur): Rename this to cr-settings-site-category. */
   is: 'cr-settings-location-page',
 
   properties: {
@@ -59,36 +60,285 @@ Polymer({
     },
 
     /**
-     * Name of the 'iron-icon' to show.
+     * What the main toggle for the category is set to (the global default when
+     * no other policy is in effect).
      */
-    icon: {
-      type: String,
-      value: 'communication:location-on',
-      readOnly: true,
+    categoryEnabled: {
+      type: Boolean,
     },
 
     /**
-     * Array of objects with url members.
+     * The ID of the category this widget is displaying data for.
+     * See |categories| for possible values.
      */
-    block: {
-      type: Array,
+    category: {
+      type: Number,
     },
 
     /**
-     * Array of objects with url members.
+     * An enum containing all the possible category numbers. Corresponds to
+     * the values found in the ContentSettingsType.

[Dan Beam, 2015/10/10 01:27:40]

we shouldn't have to copy this or make new references, I wouldn't think. 
ContentSettingsType should just live in global code

[Finnur, 2015/10/15 15:46:32]

Moved to constants.js.

      */
-    allow: {
-      type: Array,
+    categories: {
+      type: Object,
+    },
+
+    /**
+     * An enum containing the two possible values for the site list (allowed
+     * list and blocked list).
+     */
+    defaultValues: {
+      readOnly: true,
+      type: Object,
+      value: {
+        ALLOW: 1,
+        BLOCK: 2,
+        ASK: 3,

[Dan Beam, 2015/10/10 01:27:40]

this should probably be in the same constants file (assuming this is just an
enum you copied from C++)

[Finnur, 2015/10/15 15:46:32]

Ditto.

+      },
     },
   },
 
+  observers: [
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.cookies.value)',
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.javascript.value)',
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.fullscreen.value)',
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.popups.value)',
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.geolocation.value)',
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.notifications.value)',
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.media_stream_camera.value)',
+    'categoryPrefChanged_(prefs.profile.' +
+        'default_content_setting_values.media_stream_mic.value)',

[Dan Beam, 2015/10/10 01:27:40]

'categoryPrefChanged_(prefs.profile.default_content_setting_values.*)'

[Finnur, 2015/10/15 15:46:32]

Done.

+  ],
+
   ready: function() {
-    this.block = [];
-    this.allow = [];
+    CrSettingsPrefs.initialized.then(function() {
+      this.categoryEnabled = this.isPrefEnabled_(this.category);
+    }.bind(this));
+  },
+
+  /**
+   * Gets the pref at the given key. Asserts if the pref is not found.

[Dan Beam, 2015/10/10 01:27:40]

nit: Asserts -> Throws

[Finnur, 2015/10/15 15:46:32]

Done.

+   * @param {string} key

[Dan Beam, 2015/10/10 01:27:40]

key -> prefPath

[Finnur, 2015/10/15 15:46:32]

Done.

+   * @return {!chrome.settingsPrivate.PrefObject}
+   */
+  getPref_: function(key) {
+    var pref = /** @type {!chrome.settingsPrivate.PrefObject} */(
+        this.get(key, this.prefs));
+    assert(typeof pref != 'undefined', 'Pref is missing: ' + key);
+    return pref;
+  },
+
+  /**
+   * Sets the value of the pref at the given key. Asserts if the pref is not
+   * found.
+   * @param {string} key
+   * @param {*} value
+   */
+  setPrefValue_: function(key, value) {
+    this.getPref_(key);

[Dan Beam, 2015/10/10 01:27:40]

why are you calling getPref_ here?  just for the assert()?

[Finnur, 2015/10/15 15:46:32]

Hmm... redundant. Removed.

+    this.set('prefs.' + key + '.value', value);
+  },
+
+  /**
+   * Handles when the global toggle changes.
+   * @private
+   */
+  categoryPrefChanged_: function() {
+    this.categoryEnabled = this.isPrefEnabled_(this.category);
+  },
+
+  /**
+   * A handler for flipping the toggle value.
+   * @private
+   */
+  handleToggleChange_: function(event) {
+    assert(CrSettingsPrefs.isInitialized);
+
+    switch (this.category) {
+      case this.categories.COOKIES:
+      case this.categories.JAVASCRIPT:
+      case this.categories.POPUPS:
+        // "Allowed" vs "Blocked".
+        this.setPrefValue_(this.computePrefName_(this.category),
+                           this.categoryEnabled ?
+                               this.defaultValues.ALLOW :
+                               this.defaultValues.BLOCK);
+        break;
+      case this.categories.NOTIFICATION:
+      case this.categories.GEOLOCATION:
+      case this.categories.CAMERA:
+      case this.categories.MIC:
+        // "Ask" vs "Blocked".
+        this.setPrefValue_(this.computePrefName_(this.category),
+                           this.categoryEnabled ?
+                              this.defaultValues.ASK :
+                              this.defaultValues.BLOCK);
+        break;
+      case this.categories.FULLSCREEN:
+        // "Allowed" vs. "Ask first".
+        this.setPrefValue_(this.computePrefName_(this.category),
+                           this.categoryEnabled ?
+                              this.defaultValues.ALLOW :
+                              this.defaultValues.ASK);
+        break;
+      default:
+        assertNotReached();
+    }
+  },
+
+  /**
+   * Returns whether the category default is set to enabled or not.
+   * @param {number} category The category to show the icon for.
+   * @private
+   */
+  isPrefEnabled_: function(category) {
+    var pref = this.getPref_(this.computePrefName_(this.category));
+
+    // FullScreen is Allow vs. Ask.
+    if (category == this.categories.FULLSCREEN)
+      return pref.value != this.defaultValues.ALLOW;
+
+    return pref.value != this.defaultValues.BLOCK;
+  },
+
+  /**
+   * A utility function to compute the icon to use for the category.
+   * @param {number} category The category to show the icon for.
+   * @private
+   */
+  computeIcon_: function(category) {
+    // Wonder if any of these enum values are directly accessible from .js?
+    switch (category) {
+      case this.categories.COOKIES:
+        return '';  // Haven't found a good cookies icon under iron-icons.
+      case this.categories.JAVASCRIPT:
+        return 'icons:input';
+      case this.categories.FULLSCREEN:
+        return 'icons:fullscreen';
+      case this.categories.POPUPS:
+        return 'icons:open-in-new';
+      case this.categories.GEOLOCATION:
+        return 'communication:location-on';
+      case this.categories.NOTIFICATION:
+        return 'social:notifications';
+      case this.categories.CAMERA:
+        return 'av:videocam';
+      case this.categories.MIC:
+        return 'av:mic';
+      default:
+        assertNotReached();
+        return '';
+    }
+  },
+
+  /**
+   * A utility function to compute the title of the category.
+   * @param {number} category The category to show the title for.
+   * @private
+   */
+  computeTitle_: function(category) {
+    switch (category) {
+      case this.categories.COOKIES:
+        return loadTimeData.getString('siteSettingsCookies');
+      case this.categories.JAVASCRIPT:
+        return loadTimeData.getString('siteSettingsJavascript');
+      case this.categories.FULLSCREEN:
+        return loadTimeData.getString('siteSettingsFullscreen');
+      case this.categories.POPUPS:
+        return loadTimeData.getString('siteSettingsPopups');
+      case this.categories.GEOLOCATION:
+        return loadTimeData.getString('siteSettingsLocation');
+      case this.categories.NOTIFICATION:
+        return loadTimeData.getString('siteSettingsNotifications');
+      case this.categories.CAMERA:
+        return loadTimeData.getString('siteSettingsCamera');
+      case this.categories.MIC:
+        return loadTimeData.getString('siteSettingsMic');
+      default:
+        assertNotReached();
+        return '';
+    }
+  },
+
+  /**
+   * A utility function to compute the name of the pref for the category.
+   * @param {number} category The category to find the pref name for.
+   * @private
+   */
+  computePrefName_: function(category) {
+    switch (category) {
+      case this.categories.COOKIES:
+        return 'profile.default_content_setting_values.cookies';
+      case this.categories.JAVASCRIPT:
+        return 'profile.default_content_setting_values.javascript';
+      case this.categories.FULLSCREEN:
+        return 'profile.default_content_setting_values.fullscreen';
+      case this.categories.POPUPS:
+        return 'profile.default_content_setting_values.popups';
+      case this.categories.GEOLOCATION:
+        return 'profile.default_content_setting_values.geolocation';
+      case this.categories.NOTIFICATION:
+        return 'profile.default_content_setting_values.notifications';
+      case this.categories.CAMERA:
+        return 'profile.default_content_setting_values.media_stream_camera';
+      case this.categories.MIC:
+        return 'profile.default_content_setting_values.media_stream_mic';
+      default:
+        assertNotReached();
+        return '';
+    }
   },
 
-  getTitleAndCount_: function(title, count) {
-    return loadTimeData.getStringF(
-        'titleAndCount', loadTimeData.getString(title), count);
+  /**
+   * A utility function to compute the description for the category.
+   * @param {number} category The category to show the description for.
+   * @param {boolean} categoryEnabled The state of the global toggle.
+   * @private
+   */
+  computeDesc_: function(category, categoryEnabled) {
+    switch (category) {
+      case this.categories.JAVASCRIPT:
+        // "Allowed (recommended)" vs "Blocked".
+        return categoryEnabled ?
+            loadTimeData.getString('siteSettingsAllowedRecommended') :
+            loadTimeData.getString('siteSettingsBlocked');
+      case this.categories.POPUPS:
+        // "Allowed" vs "Blocked (recommended)".
+        return categoryEnabled ?
+            loadTimeData.getString('siteSettingsAllowed') :
+            loadTimeData.getString('siteSettingsBlockedRecommended');
+      case this.categories.NOTIFICATION:
+        // "Ask before sending (recommended)" vs "Blocked".
+        return categoryEnabled ?
+            loadTimeData.getString('siteSettingsAskBeforeSending') :
+            loadTimeData.getString('siteSettingsBlocked');
+      case this.categories.GEOLOCATION:
+      case this.categories.CAMERA:
+      case this.categories.MIC:
+        // "Ask before accessing (recommended)" vs "Blocked".
+        return categoryEnabled ?
+            loadTimeData.getString('siteSettingsAskBeforeAccessing') :
+            loadTimeData.getString('siteSettingsBlocked');
+      case this.categories.FULLSCREEN:
+        // "Allowed" vs. "Ask first (recommended)".
+        return categoryEnabled ?
+            loadTimeData.getString('siteSettingsAllowed') :
+            loadTimeData.getString('siteSettingsAskFirstRecommended');
+      case this.categories.COOKIES:
+        // "Allow sites to save and read cookie data" vs "Blocked".
+        return categoryEnabled ?
+            loadTimeData.getString('siteSettingsCookiesAllowed') :
+            loadTimeData.getString('siteSettingsBlocked');
+      default:
+        assertNotReached();
+        return '';
+    }
   },
 });