Remove data-scrollbar workaround

res/css/structures/_RoomView.scss

@@ -70,10 +70,6 @@ limitations under the License.
     overflow-y: auto;
     flex: 1 1 0;
     overflow-anchor: none;
-
-    &[data-scrollbar=false] {
-        overflow-y: hidden;
-    }
 }
 
 .mx_RoomView_messagePanelSearchSpinner {

src/components/structures/ScrollPanel.tsx

@@ -22,7 +22,6 @@ import AutoHideScrollbar from "./AutoHideScrollbar";
 import { getKeyBindingsManager } from "../../KeyBindingsManager";
 import ResizeNotifier from "../../utils/ResizeNotifier";
 import { KeyBindingAction } from "../../accessibility/KeyboardShortcuts";
-import UIStore, { UI_EVENTS } from "../../stores/UIStore";
 
 const DEBUG_SCROLL = false;
 
@@ -209,8 +208,6 @@ export default class ScrollPanel extends React.Component<IProps> {
 
     componentDidMount() {
         this.checkScroll();
-
-        UIStore.instance.on(UI_EVENTS.Resize, this.onUiResize);
     }
 
     componentDidUpdate() {
@@ -233,8 +230,6 @@ export default class ScrollPanel extends React.Component<IProps> {
         if (this.props.resizeNotifier) {
             this.props.resizeNotifier.removeListener("middlePanelResizedNoisy", this.onResize);
         }
-
-        UIStore.instance.off(UI_EVENTS.Resize, this.onUiResize);
     }
 
     private onScroll = ev => {
@@ -721,17 +716,6 @@ export default class ScrollPanel extends React.Component<IProps> {
         }
     }
 
-    private onUiResize = () => {
-        this.setDataScrollbar();
-    };
-
-    private setDataScrollbar(contentHeight = this.getMessagesHeight()) {
-        const sn = this.getScrollNode();
-        const minHeight = sn.clientHeight;
-        const displayScrollbar = contentHeight > minHeight;
-        sn.dataset.scrollbar = displayScrollbar.toString();
-    }
-
     // need a better name that also indicates this will change scrollTop? Rebalance height? Reveal content?
     private async updateHeight(): Promise<void> {
         // wait until user has stopped scrolling
@@ -753,7 +737,6 @@ export default class ScrollPanel extends React.Component<IProps> {
         const minHeight = sn.clientHeight;
         const height = Math.max(minHeight, contentHeight);
         this.pages = Math.ceil(height / PAGE_SIZE);
-        this.setDataScrollbar(contentHeight);
         this.bottomGrowth = 0;
         const newHeight = `${this.getListHeight()}px`;