src/vs/workbench/api/common/extHostWebviewView.ts/ExtHostWebviewViews/$resolveWebviewView
class ExtHostWebviewViews:	async $resolveWebviewView(
		webviewHandle: string,
		viewType: string,
		title: string | undefined,
		state: any,
		cancellation: CancellationToken,
	): Promise<void> {
		const entry = this._viewProviders.get(viewType);
		if (!entry) {
			throw new Error(`No view provider found for '${viewType}'`);
		}

		const { provider, extension } = entry;

		const webview = this._extHostWebview.createNewWebview(webviewHandle, { /* todo */ }, extension);
		const revivedView = new ExtHostWebviewView(webviewHandle, this._proxy, viewType, title, webview, true);

		this._webviewViews.set(webviewHandle, revivedView);

		await provider.resolveWebviewView(revivedView, { state }, cancellation);
	}