Remove unused `LeftPanel` dimension tracking (#7845)

src/components/structures/LeftPanel.tsx

@@ -64,7 +64,6 @@ interface IState {
 
 @replaceableComponent("structures.LeftPanel")
 export default class LeftPanel extends React.Component<IProps, IState> {
-    private ref = createRef<HTMLDivElement>();
     private listContainerRef = createRef<HTMLDivElement>();
     private roomSearchRef = createRef<RoomSearch>();
     private roomListRef = createRef<RoomList>();
@@ -90,7 +89,6 @@ export default class LeftPanel extends React.Component<IProps, IState> {
     }
 
     public componentDidMount() {
-        UIStore.instance.trackElementDimensions("LeftPanel", this.ref.current);
         UIStore.instance.trackElementDimensions("ListContainer", this.listContainerRef.current);
         UIStore.instance.on("ListContainer", this.refreshStickyHeaders);
         // Using the passive option to not block the main thread
@@ -420,7 +418,7 @@ export default class LeftPanel extends React.Component<IProps, IState> {
         );
 
         return (
-            <div className={containerClasses} ref={this.ref}>
+            <div className={containerClasses}>
                 <aside className="mx_LeftPanel_roomListContainer">
                     { this.renderSearchDialExplore() }
                     { this.renderBreadcrumbs() }