Add an initial implementation of the downloads MD settings page.

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 a50dd7f9852e8b54892725b0cae13f7d54a66405..f170fcaeaf1b5cd58ada5b2e0799e49685b638d8 100644
--- a/chrome/browser/resources/settings/prefs/prefs.js
+++ b/chrome/browser/resources/settings/prefs/prefs.js
@@ -34,6 +34,7 @@ Polymer('cr-settings-prefs', {
 
     this.settings = {};
     this.initializeA11y_();
+    this.initializeDownloads_();
     var observer = new ObjectObserver(this.settings);
     observer.open(this.propertyChangeCallback_.bind(this, 'settings'));
 
@@ -76,6 +77,19 @@ Polymer('cr-settings-prefs', {
   },
 
   /**
+   * Initializes some defaults for the downloads settings.
+   * @private
+   */
+  initializeDownloads_: function() {
+    this.settings.downloads = {
+      downloadLocation: '',
+      promptForDownload: false,
+    };
+
+    // TODO(jlklein): Actually pull the data out of prefs and initialize.

[Jeremy Klein, 2015/03/06 19:40:14]

nit: no need for the duplicate TODO.

[Oren Blasberg, 2015/03/06 19:53:16]

Done.

+  },
+
+  /**
    * @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.