MD Settings: tweak tap and actionable-ness of <settings-toggle-button>

chrome/browser/resources/settings/controls/settings_boolean_control_behavior.js

 // Copyright 2016 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.
 
 /**
  * @fileoverview
  * A behavior to help controls that handle a boolean preference, such as
  * checkbox and toggle button.
  */
 
 /** @polymerBehavior SettingsBooleanControlBehavior */
 var SettingsBooleanControlBehaviorImpl = {

[dschuyler, 2016/12/02 21:20:51]

Optional:
This my be my (prior) bad, but if we use
isPrefPolicyControlled(), should we add a 
behaviors: here for CrPolicyPrefBehavior?

[dschuyler, 2016/12/02 23:17:07]

Whoops, yeah, it's already being added below
on line 120.

   properties: {
     /** Whether the control should represent the inverted value. */
     inverted: {
       type: Boolean,
       value: false,
     },
 
     /** Whether the control is checked. */
     checked: {
       type: Boolean,
@@ skipping 77 matching lines @@
   /**
    * @param {*} value
    * @return {boolean} The value as a boolean, inverted if |inverted| is true.
    * @private
    */
   getNewValue_: function(value) {
     return this.inverted ? !value : !!value;
   },
 
   /**
-   * @param {boolean} disabled
-   * @param {!chrome.settingsPrivate.PrefObject} pref
    * @return {boolean} Whether the checkbox should be disabled.
    * @private
    */
-  controlDisabled_: function(disabled, pref) {
-    return disabled || this.isPrefPolicyControlled(pref);
+  controlDisabled_: function() {
+    return this.disabled || this.isPrefPolicyControlled(assert(this.pref));

[dschuyler, 2016/12/02 21:20:51]

Is the error within isPrefPolicyControlled unclear when this.pref is not set?
I'm curious about how much the assert is adding/helping.

[Dan Beam, 2016/12/02 23:09:10]

it's required to closure compile.  this.pref should always be set.

[dschuyler, 2016/12/02 23:17:08]

Okay. I wonder if an if() or something could check the var and make closure
happy. It looks like we may be importing a file and making a runtime function
call for the closure compiler.

[Dan Beam, 2016/12/02 23:21:28]

we are doing both of those things, BUT:

a) assert.html will be de-duped, it's used many many many times throughout our
page but every subsequent <link rel=import> is ignored

b) there are many places that run assert() and it's a good thing that we're
checking that this.pref is set.  because if not, there's problems.

   },
 };
 
 /** @polymerBehavior */
 var SettingsBooleanControlBehavior = [
   CrPolicyPrefBehavior,

[Dan Beam, 2016/12/02 23:09:10]

^ do you mean add this behavior?

[dschuyler, 2016/12/02 23:17:07]

I totally do. 

   PrefControlBehavior,
   SettingsBooleanControlBehaviorImpl,
 ];