src/vs/workbench/contrib/extensions/browser/extensionsViewlet.ts/ExtensionsViewPaneContainer/isSupportedDragElement
class ExtensionsViewPaneContainer:	private isSupportedDragElement(e: DragEvent): boolean {
		if (e.dataTransfer) {
			const typesLowerCase = e.dataTransfer.types.map(t => t.toLocaleLowerCase());
			return typesLowerCase.indexOf('files') !== -1;
		}

		return false;
	}