Move window border widget into layout service

Part of #104508

src/vs/workbench/browser/layout.ts

@@ -1616,6 +1616,10 @@ export abstract class Layout extends Disposable implements IWorkbenchLayoutServi
 		return this.state.windowBorder;
 	}
 
+	getWindowBorderWidth(): number {
+		return this.state.windowBorder ? 2 : 0;
+	}
+
 	getWindowBorderRadius(): string | undefined {
 		return this.state.windowBorder && isMacintosh ? '5px' : undefined;
 	}

src/vs/workbench/services/hover/browser/hoverWidget.ts

@@ -143,7 +143,7 @@ export class HoverWidget extends Widget {
 		// Get horizontal alignment and position
 		let targetLeft = this._target.x !== undefined ? this._target.x : Math.min(...targetBounds.map(e => e.left));
 		if (targetLeft + this._hover.containerDomNode.clientWidth >= document.documentElement.clientWidth) {
-			this._x = document.documentElement.clientWidth - (this._workbenchLayoutService.hasWindowBorder() ? 3 : 1);
+			this._x = document.documentElement.clientWidth - this._workbenchLayoutService.getWindowBorderWidth() - 1;
 			this._hover.containerDomNode.classList.add('right-aligned');
 		} else {
 			this._x = targetLeft;

src/vs/workbench/services/layout/browser/layoutService.ts

@@ -144,6 +144,11 @@ export interface IWorkbenchLayoutService extends ILayoutService {
 	 */
 	hasWindowBorder(): boolean;
 
+	/**
+	 * Returns the window border width.
+	 */
+	getWindowBorderWidth(): number;
+
 	/**
 	 * Returns the window border radius if any.
 	 */

src/vs/workbench/test/browser/workbenchTestServices.ts

@@ -429,6 +429,7 @@ export class TestLayoutService implements IWorkbenchLayoutService {
 	hasFocus(_part: Parts): boolean { return false; }
 	focusPart(_part: Parts): void { }
 	hasWindowBorder(): boolean { return false; }
+	getWindowBorderWidth(): number { return 0; }
 	getWindowBorderRadius(): string | undefined { return undefined; }
 	isVisible(_part: Parts): boolean { return true; }
 	getDimension(_part: Parts): Dimension { return new Dimension(0, 0); }