ServiceWorker: Make a way to retrieve a service worker version id (Blink)

Source/web/FrameLoaderClientImpl.cpp

Index: Source/web/FrameLoaderClientImpl.cpp
diff --git a/Source/web/FrameLoaderClientImpl.cpp b/Source/web/FrameLoaderClientImpl.cpp
index 107504056be14563f79a833c878ac0f713516dbe..f76882975b9aa0a6081406973539e328c9e50581 100644
--- a/Source/web/FrameLoaderClientImpl.cpp
+++ b/Source/web/FrameLoaderClientImpl.cpp
@@ -835,6 +835,13 @@ bool FrameLoaderClientImpl::isControlledByServiceWorker(DocumentLoader& loader)
     return m_webFrame->client() && m_webFrame->client()->isControlledByServiceWorker(*WebDataSourceImpl::fromDocumentLoader(&loader));
 }
 
+int64_t FrameLoaderClientImpl::serviceWorkerID(DocumentLoader& loader)
+{
+    if (!m_webFrame->client())
+        return -1;
+    return m_webFrame->client()->serviceWorkerID(*WebDataSourceImpl::fromDocumentLoader(&loader));
+}
+
 SharedWorkerRepositoryClient* FrameLoaderClientImpl::sharedWorkerRepositoryClient()
 {
     return m_webFrame->sharedWorkerRepositoryClient();