Go through root to get loading clients in StyleSheetContents::checkLoaded.

Source/core/css/StyleSheetContents.cpp

Index: Source/core/css/StyleSheetContents.cpp
diff --git a/Source/core/css/StyleSheetContents.cpp b/Source/core/css/StyleSheetContents.cpp
index ef527fcb3dc3f82477c3ff4cd70c8858046eb7c0..423fb4e204a8b9cdc65fa29a9f726557f6617894 100644
--- a/Source/core/css/StyleSheetContents.cpp
+++ b/Source/core/css/StyleSheetContents.cpp
@@ -404,7 +404,7 @@ void StyleSheetContents::checkLoaded()
     // to the set of completed clients. We therefore need the copy in order to
     // not modify the set while iterating it.
     WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet> > loadingClients;
-    copyToVector(m_loadingClients, loadingClients);
+    copyToVector(root->m_loadingClients, loadingClients);
 
     for (unsigned i = 0; i < loadingClients.size(); ++i) {
         if (loadingClients[i]->loadCompleted())