text: var FPSCallback = (function () {
      function FPSCallback(onFrame) {
          var _this = this;
          this.running = false;
          this.onFrame = onFrame;
          this.impl = new android.view.Choreographer.FrameCallback({
              doFrame: function (nanos) {
                  _this.handleFrame(nanos);
              }
          });
      }
      FPSCallback.prototype.start = function () {
          if (this.running) {
              return;
          }
          android.view.Choreographer.getInstance().postFrameCallback(this.impl);
          this.running = true;
      };
      FPSCallback.prototype.stop = function () {
          if (!this.running) {
              return;
          }
          android.view.Choreographer.getInstance().removeFrameCallback(this.impl);
          this.running = false;
      };
      FPSCallback.prototype.handleFrame = function (nanos) {
          if (!this.running) {
              return;
          }
          this.onFrame(nanos / 1000000);
          android.view.Choreographer.getInstance().postFrameCallback(this.impl);
      };
      return FPSCallback;
  }());
  exports.FPSCallback = FPSCallback;
  