src/vs/workbench/browser/parts/editor/editorDropTarget.ts/DropOverlay/doPositionOverlay
class DropOverlay:	private doPositionOverlay(options: { top: string, left: string, width: string, height: string }): void {
		const [container, overlay] = assertAllDefined(this.container, this.overlay);

		// Container
		const offsetHeight = this.getOverlayOffsetHeight();
		if (offsetHeight) {
			container.style.height = `calc(100% - ${offsetHeight}px)`;
		} else {
			container.style.height = '100%';
		}

		// Overlay
		overlay.style.top = options.top;
		overlay.style.left = options.left;
		overlay.style.width = options.width;
		overlay.style.height = options.height;
	}