Service Worker: Migrate to version_uuid and surface ServiceWorker.id. (Blink 1/3)

Source/web/FrameLoaderClientImpl.cpp

Index: Source/web/FrameLoaderClientImpl.cpp
diff --git a/Source/web/FrameLoaderClientImpl.cpp b/Source/web/FrameLoaderClientImpl.cpp
index a6a99aeed60b19284e9356d004fdb3823a60b830..60ccfd500a210366f4f28b25a3ff2120412f0b74 100644
--- a/Source/web/FrameLoaderClientImpl.cpp
+++ b/Source/web/FrameLoaderClientImpl.cpp
@@ -912,10 +912,10 @@ bool FrameLoaderClientImpl::isControlledByServiceWorker(DocumentLoader& loader)
     return m_webFrame->client() && m_webFrame->client()->isControlledByServiceWorker(*WebDataSourceImpl::fromDocumentLoader(&loader));
 }
 
-int64_t FrameLoaderClientImpl::serviceWorkerID(DocumentLoader& loader)
+std::string FrameLoaderClientImpl::serviceWorkerID(DocumentLoader& loader)
 {
     if (!m_webFrame->client())
-        return -1;
+        return std::string();
     return m_webFrame->client()->serviceWorkerID(*WebDataSourceImpl::fromDocumentLoader(&loader));
 }