Play a chime when the hotword is triggered.

chrome/browser/resources/hotword/state_manager.js

Index: chrome/browser/resources/hotword/state_manager.js
diff --git a/chrome/browser/resources/hotword/state_manager.js b/chrome/browser/resources/hotword/state_manager.js
index 2727cbcd8af7cf76ee799f1d8790d071e2cc9d3a..9cf207de834c2d662698b1ef0ee1cd1f623d147f 100644
--- a/chrome/browser/resources/hotword/state_manager.js
+++ b/chrome/browser/resources/hotword/state_manager.js
@@ -43,8 +43,18 @@ cr.define('hotword', function() {
      */
     this.sessionStartedCb_ = null;
 
+    /**
+     * Hotword trigger audio notification... a.k.a The Chime (tm)

[rpetterson, 2014/09/16 07:55:45]

nit: end with period.

+     * @private {!Audio}
+     */
+    this.chime_ = document.createElement('audio');
+
     // Get the initial status.
     chrome.hotwordPrivate.getStatus(this.handleStatus_.bind(this));
+
+    // Setup the chime and insert into the page.
+    this.chime_.src = chrome.extension.getURL('chime.wav');
+    document.body.appendChild(this.chime_);
   }
 
   /**
@@ -227,6 +237,9 @@ cr.define('hotword', function() {
       // Detector implicitly stops when the hotword is detected.
       this.state_ = State_.STOPPED;
 
+      // Play the chime.
+      this.chime_.play();
+
       chrome.hotwordPrivate.notifyHotwordRecognition('search', function() {});
 
       // Implicitly clear the session. A session needs to be started in order to