Set up serving infrastructure for c/b/r/settings.

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

 /* Copyright 2015 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
  * 'cr-settings-prefs' is an element which serves as a model for
  * interaction with settings which are stored in Chrome's
  * Preferences.
  *
@@ skipping 57 matching lines @@
       enableTapDragging: false,
     };
 
     // ChromeVox is enbaled/disabled via the 'settings.accessibility' boolean
     // pref.
     this.settings.accessibility = false;
 
     // TODO(jlklein): Actually pull the data out of prefs and initialize.
   },
 
+   /**
+   * Converts a camel-case property name to the prefs underscore format.
+   * @param {string} camelCaseName
+   * @return {string} The name with underscores instead of dashes.
+   * @private
+   */
+  camelCaseToUnderscores_: function(camelCaseName) {
+    return camelCaseName.replace(/([A-Z])/g, function($1) {
+      return '_' + $1.toLowerCase();
+    });
+  },
+
   /**
    * @param {string} propertyPath The path before the property names.
    * @param {!Array<string>} added An array of keys which were added.
    * @param {!Array<string>} removed An array of keys which were removed.
    * @param {!Array<string>} changed An array of keys of properties whose
    *     values changed.
    * @param {function(string) : *} getOldValueFn A function which takes a
    *     property name and returns the old value for that property.
    * @private
    */
   propertyChangeCallback_: function(
       propertyPath, added, removed, changed, getOldValueFn) {
     Object.keys(changed).forEach(function(property) {
+      var pref = this.camelCaseToUnderscores_(`${propertyPath}.${property}`);
+      var value = changed[property];
       console.log(
-          `${propertyPath}.${property}`,
+          pref,
           `old : ${getOldValueFn(property)}`,
-          `newValue : ${changed[property]}`);
+          `newValue : ${value}`);
 
       // TODO(jlklein): Actually set the changed property back to prefs.
-    });
+    }.bind(this));
    },
 });