MD Settings: Migrate site settings media-picker to native select.

chrome/browser/resources/settings/site_settings/media_picker.js

Index: chrome/browser/resources/settings/site_settings/media_picker.js
diff --git a/chrome/browser/resources/settings/site_settings/media_picker.js b/chrome/browser/resources/settings/site_settings/media_picker.js
index 847213c0b384ae3f015b6a42a60aeb55b0dd7223..829b74a41609670f2284f6c06ed3bde5a9931090 100644
--- a/chrome/browser/resources/settings/site_settings/media_picker.js
+++ b/chrome/browser/resources/settings/site_settings/media_picker.js
@@ -44,14 +44,20 @@ Polymer({
     this.$.picker.hidden = devices.length == 0;
     if (devices.length > 0) {
       this.devices = devices;
-      this.$.mediaPicker.selected = defaultDevice;
+
+      // Wait for <select> to be populated.
+      this.async(function() {
+        this.$.mediaPicker.value = defaultDevice;
+      }.bind(this));
     }
   },
 
   /**
    * A handler for when an item is selected in the media picker.
+   * @private
    */
-  onMediaPickerActivate_: function(event) {
-    this.browserProxy.setDefaultCaptureDevice(this.type, event.detail.selected);
+  onChange_: function() {
+    this.browserProxy.setDefaultCaptureDevice(
+        this.type, this.$.mediaPicker.value);
   },
 });