Add buffering events.

Closes #25.

Change-Id: I0acac7195de6ddfc1386fa9334b0c2e278389a04

lib/player/player.js

@@ -50,14 +50,23 @@ goog.require('shaka.util.Uint8ArrayUtils');
  */
 
 
+/**
+ * @event shaka.player.Player.BufferingEvent
+ * @description Fired when the player's buffering state changes.
+ * @property {string} type 'bufferingStart' or 'bufferingEnd'
+ * @export
+ */
+
+
 
 /**
  * Creates a Player.
  *
  * @param {!HTMLVideoElement} video The video element.
  *
+ * @fires shaka.media.Stream.AdaptationEvent
+ * @fires shaka.player.Player.BufferingEvent
  * @fires shaka.player.Player.ErrorEvent
- * @fires shaka.dash.DashStream.AdaptationEvent
  *
  * @constructor
  * @extends {shaka.util.FakeEventTarget}
@@ -1191,6 +1200,7 @@ shaka.player.Player.prototype.onWatchdogTimer_ = function() {
       this.stats_.logBufferingEvent();
       shaka.timer.begin('buffering');
       shaka.log.debug('Buffering...');
+      this.dispatchEvent(shaka.util.FakeEvent.create({type: 'bufferingStart'}));
     }
   } else {
     var resumeThreshold = this.videoSource_.getResumeThreshold();
@@ -1200,6 +1210,7 @@ shaka.player.Player.prototype.onWatchdogTimer_ = function() {
       shaka.timer.end('buffering');
       this.stats_.logBufferingTime(shaka.timer.get('buffering'));
       this.buffering_ = false;
+      this.dispatchEvent(shaka.util.FakeEvent.create({type: 'bufferingEnd'}));
       this.video_.play();
     }
   }