message: feat(wx): use ctx.draw() for weixin application
diff: @@ -14,6 +14,7 @@ import timsort from './core/timsort';
  import Layer from './Layer';
  import requestAnimationFrame from './animation/requestAnimationFrame';
  import Image from './graphic/Image';
  +import env from './core/env';
  // PENDIGN
  // Layer exceeds MAX_PROGRESSIVE_LAYER_NUMBER may have some problem when flush directly second time.
  @@ -548,6 +549,15 @@ Painter.prototype = {
  // ctx.restore();
  // }
  + if (env.wxa) {
  + // Flush for weixin application
  + util.each(this._layers, function (layer) {
  + if (layer && layer.ctx && layer.ctx.draw) {
  + layer.ctx.draw();
  + }
  + });
  + }
  +
  this._furtherProgressive = false;
  util.each(this._progressiveLayers, function (layer) {
  if (layer.__maxProgress >= layer.__progress) {
  