src/vs/workbench/contrib/webviewPanel/browser/webviewWorkbenchService.ts/WebviewEditorService/resolveWebview
class WebviewEditorService:	public resolveWebview(webview: WebviewInput): CancelablePromise<void> {
		return createCancelablePromise(async (cancellation) => {
			const didRevive = await this.tryRevive(webview, cancellation);
			if (!didRevive) {
				// A reviver may not be registered yet. Put into pool and resolve promise when we can revive
				return this._revivalPool.enqueueForRestoration(webview, cancellation);
			}
		});
	}