Allow ConfirmDialog to confirm disabling options.

chrome/browser/resources/options/confirm_dialog.js

Index: chrome/browser/resources/options/confirm_dialog.js
diff --git a/chrome/browser/resources/options/confirm_dialog.js b/chrome/browser/resources/options/confirm_dialog.js
index bb9bd4e786caf94738210bf154e061e9d7b4f2c2..8c547eee989e58afec8440565024f3d21ef028f2 100644
--- a/chrome/browser/resources/options/confirm_dialog.js
+++ b/chrome/browser/resources/options/confirm_dialog.js
@@ -22,10 +22,12 @@ cr.define('options', function() {
    *     user has confirmed the dialog before. This ensures that the user is
    *     presented with the dialog only once. If left |undefined|, the dialog
    *     will pop up every time the user attempts to set |pref| to |true|.
+   * @param {boolean} opt_confirmValue The value to which changing should

[dpapad, 2016/05/16 17:09:53]

The naming of this param suggests that it is optional, which means that the
annotation should be
@param {boolean=}

[dspaid, 2016/05/16 23:33:22]

Done.

+   * trigger the confirmation dialog.  Defaults to |true| if left |undefined|.

[stevenjb, 2016/05/16 16:19:48]

indent

[dspaid, 2016/05/16 23:33:22]

Done.

    * @extends {options.SettingsDialog}
    */
   function ConfirmDialog(name, title, pageDivName, okButton, cancelButton, pref,
-                         metric, opt_confirmedPref) {
+                         metric, opt_confirmedPref, opt_confirmValue) {
     SettingsDialog.call(this, name, title, pageDivName, okButton, cancelButton);
 
     /** @protected */
@@ -39,6 +41,10 @@ cr.define('options', function() {
 
     /** @private */
     this.confirmed_ = false;
+
+    /** @private */
+    this.confirmValue_ = opt_confirmValue === undefined ||

[dpapad, 2016/05/16 17:09:53]

This logic is fragile. In almost all JS APIs I have encountered, null/undefined
is treated the same when it comes to optional parameters. Here it is not, if
null is passed, this.confirmValue_ will be false, if undefined is passed, it
will be true.

One option would be to simply check for both null and undefined and treat them
the same.

[dspaid, 2016/05/16 23:33:22]

Good point.  changing === to == should also do the trick.

+        Boolean(opt_confirmValue);
   }
 
   ConfirmDialog.prototype = {
@@ -57,7 +63,7 @@ cr.define('options', function() {
       if (!event.value.uncommitted)
         return;
 
-      if (event.value.value && !this.confirmed_)
+      if (event.value.value == this.confirmValue_ && !this.confirmed_)
         PageManager.showPageByName(this.name, false);
       else
         Preferences.getInstance().commitPref(this.pref, this.metric);
@@ -97,7 +103,8 @@ cr.define('options', function() {
 
       Preferences.getInstance().commitPref(this.pref, this.metric);
       if (this.confirmedPref_)
-        Preferences.setBooleanPref(this.confirmedPref_, true, true);
+        Preferences.setBooleanPref(
+            this.confirmedPref_, this.confirmValue, true);

[dpapad, 2016/05/16 17:09:53]

Underscore missing! This is not referring to the member var this.confirmValue_.
I am hoping that the JS Compiler would catch this, or a test.

[dspaid, 2016/05/16 23:33:22]

Done.
Oddly enough the compiler didn't seem to complain, though maybe I was just
looking in the wrong place.

     },
 
     /**