src/vs/workbench/contrib/extensions/browser/extensionsWorkbenchService.ts/ExtensionsWorkbenchService/fromGallery
class ExtensionsWorkbenchService:	private fromGallery(gallery: IGalleryExtension, extensionsControlManifest: IExtensionsControlManifest): IExtension {
		let extension = this.getInstalledExtensionMatchingGallery(gallery);
		if (!extension) {
			extension = this.instantiationService.createInstance(Extension, ext => this.getExtensionState(ext), ext => this.getReloadStatus(ext), undefined, undefined, gallery);
			Extensions.updateExtensionFromControlManifest(<Extension>extension, extensionsControlManifest);
		}
		return extension;
	}