[improvement] sort out utils (#2672)

packages/mixins/popup/index.js

@@ -1,8 +1,8 @@
 import manager from './manager';
 import context from './context';
-import scrollUtils from '../../utils/scroll';
-import { on, off } from '../../utils/event';
 import Touch from '../touch';
+import { on, off } from '../../utils/event';
+import { getScrollEventTarget } from '../../utils/scroll';
 
 export default {
   mixins: [Touch],
@@ -159,7 +159,7 @@ export default {
     onTouchMove(e) {
       this.touchMove(e);
       const direction = this.deltaY > 0 ? '10' : '01';
-      const el = scrollUtils.getScrollEventTarget(e.target, this.$el);
+      const el = getScrollEventTarget(e.target, this.$el);
       const { scrollHeight, offsetHeight, scrollTop } = el;
       let status = '11';