Disable sounds in the virtual keyboard.

BUG=368255

Review URL: https://codereview.chromium.org/259183003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@267085 0039d316-1c4b-4281-b951-d872f2087c98

ui/keyboard/resources/constants.js

@@ -105,3 +105,9 @@ var RESIZE_THRESHOLD = 20;
  * @type {number}
  */
 var SOUND_POOL_SIZE = 10;
+
+/**
+ * Whether or not to enable sounds on key press.
+ * @type {boolean}
+ */
+var SOUND_ENABLED = false;

ui/keyboard/resources/elements/kb-keyboard.js

@@ -770,7 +770,7 @@ Polymer('kb-keyboard', {
    * @param {Sound} sound The id of the audio tag.
    */
   playSound: function(sound) {
-    if (!sound || sound == Sound.NONE)
+    if (!SOUND_ENABLED || !sound || sound == Sound.NONE)
       return;
     var pool = this.sounds[sound];
     if (!pool) {