MD Settings: Content Settings: Support guest mode.

chrome/browser/resources/settings/site_settings/category_default_setting.js

Index: chrome/browser/resources/settings/site_settings/category_default_setting.js
diff --git a/chrome/browser/resources/settings/site_settings/category_default_setting.js b/chrome/browser/resources/settings/site_settings/category_default_setting.js
index 4496d23e2260f77e2f4689b6d649079fff086fcc..e3cfdfe8d1ac6f98ebb5875eea4fc3c05bfc45ba 100644
--- a/chrome/browser/resources/settings/site_settings/category_default_setting.js
+++ b/chrome/browser/resources/settings/site_settings/category_default_setting.js
@@ -199,4 +199,13 @@ Polymer({
                 categoryEnabled ? this.toggleOnLabel : this.toggleOffLabel;
           }.bind(this));
   },
+
+  /**
+   * @return {boolean}
+   * @private
+   */
+  isToggleEnabled_: function() {

[tommycli, 2017/02/14 00:28:39]

since it's only disabled if it's on POPUPS AND in guest mode, (disabling is the
exceptional case), consider making this isToggleDisabled, and get rid of the !
in the binding.

That would be easier to grok for me, but i realize this is kind of subjective.

[stevenjb, 2017/02/14 00:49:23]

Hmm, I thought we had more disabled$="[[!isFooEnabled]]" than [[isFooDisabled]]
in Settings, but we appear to be split. I don't feel strongly, so done.

+    return this.category != settings.ContentSettingsTypes.POPUPS ||
+        !loadTimeData.getBoolean('isGuest');
+  }
 });