无JIRA任务 debounce改一下

src/base/list/virtualgrouplist.js

@@ -55,18 +55,10 @@ BI.VirtualGroupList = BI.inherit(BI.Widget, {
     mounted: function () {
         var self = this, o = this.options;
         this._populate();
-        this._debounceRelease = BI.debounce(function () {
-            self._scrollLock = false;
-        }, 30);
-        this.element.scroll(function (e) {
-            if (self._scrollLock === true) {
-                return;
-            }
-            self._scrollLock = true;
+        this.element.scroll(BI.debounce(function (e) {
             o.scrollTop = self.element.scrollTop();
-            self._debounceRelease();
             self._calculateBlocksToRender();
-        });
+        }, 30));
         BI.ResizeDetector.addResizeListener(this, function () {
             self._calculateBlocksToRender();
         });