added _startTime var to FlxGame to handle specifics of Lib.getTimer()…

… on js target

flixel/FlxGame.hx

@@ -97,6 +97,12 @@ class FlxGame extends Sprite
 	 * Total number of milliseconds elapsed since game start.
 	 */
 	private var _total:Int = 0;
+	/**
+	 * Time stamp of game startup. 
+	 * Need to add this var for js target where Lib.getTimer() returns time stamp of current date, 
+	 * not the time passed since app start.
+	 */
+	private var _startTime:Int = 0;
 	/**
 	 * Total number of milliseconds elapsed since last update loop.
 	 * Counts down as we step through the game loop.
@@ -282,6 +288,7 @@ class FlxGame extends Sprite
 		removeEventListener(Event.ADDED_TO_STAGE, create);
 
 		_total = getTimer();
+		_startTime = _total;
 
 		#if desktop
 		FlxG.fullscreen = _startFullscreen;
@@ -492,7 +499,7 @@ class FlxGame extends Sprite
 	 */
 	private function onEnterFrame(_):Void
 	{
-		ticks = getTimer();
+		ticks = getTimer() - _startTime;
 		_elapsedMS = ticks - _total;
 		_total = ticks;