MD Settings: make [un]controlled radio buttons actionable (cursor: pointer)

chrome/browser/resources/settings/controls/controlled_radio_button.html

Index: chrome/browser/resources/settings/controls/controlled_radio_button.html
diff --git a/chrome/browser/resources/settings/controls/controlled_radio_button.html b/chrome/browser/resources/settings/controls/controlled_radio_button.html
index c19f779f335fdba05cf49336558622e7b2ff0417..b59221d327e8ad116a15424027e7888308a7c788 100644
--- a/chrome/browser/resources/settings/controls/controlled_radio_button.html
+++ b/chrome/browser/resources/settings/controls/controlled_radio_button.html
@@ -83,6 +83,10 @@
                    --primary-text-color);
       }
 
+      :host(:not([controlled_])) {

[dpapad, 2017/04/18 18:58:32]

Can radio buttons be disabled otherwise? For example with a |disabled|
attribute?

Would it be more robust as follows?

:host {
  ....
  @apply(--settings-actionable);
}

:host([controlled_]),
:host([disabled]) {
  cursor: initial;
  pointer-events: none;
}

[Dan Beam, 2017/04/18 19:00:37]

no

[Dan Beam, 2017/04/18 19:10:49]

that was the short answer.  the longer answer is that assuming what will be in a
CSS mixin to override it is not the best strategy, imo.  it also makes less
sense to me to apply a style then override it later... instead of only applying
it when needed.

[Dan Beam, 2017/04/18 19:12:22]

also, i'm not really sure how [disabled] works in the context.  most of this
file uses a private |controlled_| and determines it's own fate, whereas disabled
(if it's public, especially) can be set by the outside.  we generally want to
keep things private / up to the minimal scope possible until needed otherwise
(i.e. something outside of this class needs to disable this for reasons a
<controlled-radio-button> shouldn't really know about)

+        @apply(--settings-actionable);
+      }
+
       :host([controlled_]) {
         /* Disable pointer events for this whole element, as outer on-tap gets
          * triggered when clicking/tapping anywhere in :host. */