src/vs/workbench/api/common/extHostExtensionService.ts/AbstractExtHostExtensionService/activateByIdWithErrors
class AbstractExtHostExtensionService:	public activateByIdWithErrors(extensionId: ExtensionIdentifier, reason: ExtensionActivationReason): Promise<void> {
		return this._activateById(extensionId, reason).then(() => {
			const extension = this._activator.getActivatedExtension(extensionId);
			if (extension.activationFailed) {
				// activation failed => bubble up the error as the promise result
				return Promise.reject(extension.activationFailedError);
			}
			return undefined;
		});
	}