Support lists in <cr-settings-pref>

chrome/browser/resources/settings/prefs/prefs.js

Index: chrome/browser/resources/settings/prefs/prefs.js
diff --git a/chrome/browser/resources/settings/prefs/prefs.js b/chrome/browser/resources/settings/prefs/prefs.js
index 9b311e84aa6336970fb326524d2f41cabd38ce0b..6c9c462bdc7b7e54b2bec78cfe158e4b48bf7597 100644
--- a/chrome/browser/resources/settings/prefs/prefs.js
+++ b/chrome/browser/resources/settings/prefs/prefs.js
@@ -52,7 +52,8 @@ PrefWrapper.prototype.equals = function(other) {
 function ListPrefWrapper(prefObj) {
   // Copy the array so changes to prefObj aren't reflected in this.value_.
   // TODO(michaelpg): Do a deep copy to support nested lists and objects.
-  this.value_ = prefObj.value.slice();
+  this.value_ = PrefWrapper.deepCopy(prefObj.value);
+//  this.value_ = prefObj.value.slice();
 }
 
   ListPrefWrapper.prototype = {
@@ -63,20 +64,85 @@ function ListPrefWrapper(prefObj) {
    * @override
    */
   equals: function(other) {
-    'use strict';
     assert(this.key_ == other.key_);
-    if (this.value_.length != other.value_.length)
+    return PrefWrapper.objectsEqual(this.value_, other.value_);
+  },
+};
+
+/**
+ * @constructor
+ * @extends {PrefWrapper}
+ * @param {!chrome.settingsPrivate.PrefObject} prefObj
+ */
+function DictPrefWrapper(prefObj) {
+  // Copy the object so changes to prefObj aren't reflected in this.value_.
+  // TODO(michaelpg): Do a deep copy to support nested lists and objects.
+  this.value_ = prefObj.value.slice();
+}
+
+  DictPrefWrapper.prototype = {
+  __proto__: PrefWrapper.prototype,
+
+  /**
+   * Tests whether two DictPrefWrapper values contain the same list items.
+   * @override
+   */
+  equals: function(other) {
+    assert(this.key_ == other.key_);
+    return PrefWrapper.objectsEqual(this.value_, other.value_);
+  },
+};
+
+(function() {
+'use strict';
+
+PrefWrapper.objectsEqual = function(obj1, obj2) {
+  if (Array.isArray(obj1)) {
+    if (!Array.isArray(obj2))
+      return false;
+    if (obj1.length != obj2.length)
       return false;
-    for (let i = 0; i < this.value_.length; i++) {
-      if (this.value_[i] != other.value_[i])
+    if (obj1 == obj2) {
+      return true;
+    }
+    for (var i = 0; i < obj1.length; i++) {
+      if (!PrefWrapper.objectsEqual(obj1[i], obj2[i])) {
         return false;
+      }
+      else if (typeof obj1[i] == 'object') {
+      }
     }
     return true;
-  },
+  }
+  if (typeof obj1 == 'object') {
+     var props1 = Object.keys(obj1);
+     var props2 = Object.keys(obj2);
+     if (props1.length != props2.length)
+       return false;
+     for (var prop of props1) {
+       if (!PrefWrapper.objectsEqual(obj1[prop], obj2[prop]))
+         return false;
+     }
+     return true;
+  }
+  return obj1 == obj2;
+};
+
+PrefWrapper.deepCopy = function(obj) {
+  if (Array.isArray(obj)) {
+    var copy = [];
+    for (let el of obj)
+      copy.push(PrefWrapper.deepCopy(el));
+    return copy;
+  }
+  if (typeof obj == 'object') {
+    var copy = {};
+    for (let prop in obj)
+      copy[prop] = PrefWrapper.deepCopy(obj[prop]);
+  }
+  return obj;
 };
 
-(function() {
-  'use strict';
 
   Polymer({
     is: 'cr-settings-prefs',
@@ -146,8 +212,11 @@ function ListPrefWrapper(prefObj) {
       // If settingsPrivate already has this value, do nothing. (Otherwise,
       // a change event from settingsPrivate could make us call
       // settingsPrivate.setPref and potentially trigger an IPC loop.)
-      if (prefWrapper.equals(this.createPrefWrapper_(prefObj)))
+      //
+      // this copy is a waste
+      if (PrefWrapper.objectsEqual(prefWrapper.value_, this.createPrefWrapper_(prefObj).value_)) {
         return;
+      }
 
       this.settingsApi_.setPref(
           key,