Fixes #21857: Handle a ViewScrollRequestEvent in a single place

src/vs/editor/browser/view/viewImpl.ts

@@ -516,7 +516,12 @@ export class View extends ViewEventHandler implements editorBrowser.IView, IDisp
 		this.outgoingEvents.emitScrollChanged(e);
 		return false;
 	}
-	public onScrollRequest(e: editorCommon.ICursorScrollRequestEvent): boolean {
+	public onScrollRequest(e: viewEvents.ViewScrollRequestEvent): boolean {
+		let currentScrollTop = this.layoutProvider.getScrollTop();
+		let newScrollTop = currentScrollTop + e.deltaLines * this._context.configuration.editor.lineHeight;
+		this.layoutProvider.setScrollPosition({
+			scrollTop: newScrollTop
+		});
 		return e.revealCursor ? this.revealCursor() : false;
 	}
 	private revealCursor(): boolean {

src/vs/editor/browser/viewParts/lines/viewLines.ts

@@ -197,14 +197,7 @@ export class ViewLines extends ViewPart implements IVisibleLinesHost<ViewLine>,
 		this.domNode.setWidth(e.scrollWidth);
 		return this._visibleLines.onScrollChanged(e) || true;
 	}
-	public onScrollRequest(e: viewEvents.ViewScrollRequestEvent): boolean {
-		let currentScrollTop = this._viewLayout.getScrollTop();
-		let newScrollTop = currentScrollTop + e.deltaLines * this._lineHeight;
-		this._viewLayout.setScrollPosition({
-			scrollTop: newScrollTop
-		});
-		return true;
-	}
+
 	public onTokensChanged(e: viewEvents.ViewTokensChangedEvent): boolean {
 		return this._visibleLines.onTokensChanged(e);
 	}