Revert "cache panel body size"

This reverts commit febf978c.

fixes #61450

src/vs/base/browser/ui/splitview/panelview.ts

@@ -46,6 +46,7 @@ export abstract class Panel implements IView {
 	protected _expanded: boolean;
 	protected disposables: IDisposable[] = [];
 
+	private expandedSize: number | undefined = undefined;
 	private _headerVisible = true;
 	private _minimumBodySize: number;
 	private _maximumBodySize: number;
@@ -54,9 +55,6 @@ export abstract class Panel implements IView {
 
 	private header: HTMLElement;
 
-	private cachedExpandedSize: number | undefined = undefined;
-	private cachedBodySize: number | undefined = undefined;
-
 	private _onDidChange = new Emitter<number | undefined>();
 	readonly onDidChange: Event<number | undefined> = this._onDidChange.event;
 
@@ -131,7 +129,7 @@ export abstract class Panel implements IView {
 
 		this._expanded = !!expanded;
 		this.updateHeader();
-		this._onDidChange.fire(expanded ? this.cachedExpandedSize : undefined);
+		this._onDidChange.fire(expanded ? this.expandedSize : undefined);
 	}
 
 	get headerVisible(): boolean {
@@ -192,14 +190,8 @@ export abstract class Panel implements IView {
 		const headerSize = this.headerVisible ? Panel.HEADER_SIZE : 0;
 
 		if (this.isExpanded()) {
-			const bodySize = size - headerSize;
-
-			if (bodySize !== this.cachedBodySize) {
-				this.layoutBody(bodySize);
-				this.cachedBodySize = bodySize;
-			}
-
-			this.cachedExpandedSize = size;
+			this.layoutBody(size - headerSize);
+			this.expandedSize = size;
 		}
 	}