Added loopTime property to keep track of the time at which the sound loop source should actually start playback based on BaseAudioContext.currentTime value

Author: pavle-goloskokovic

v3/src/sound/webaudio/WebAudioSound.js

@@ -62,6 +62,14 @@ var WebAudioSound = new Class({
          * @property {number} startTime
          */
         this.startTime = 0;
+        /**
+         * The time at which the sound loop source should actually start playback.
+         * Based on BaseAudioContext.currentTime value.
+         *
+         * @private
+         * @property {number} loopTime
+         */
+        this.loopTime = 0;
         /**
          * An array where we keep track of all rate updates during playback.
          *