Merge m-c to inbound.

content/base/src/nsStyleLinkElement.cpp

@@ -316,12 +316,14 @@ nsStyleLinkElement::DoUpdateStyleSheet(nsIDocument *aOldDocument,
     }
   }
 
-  if (mDontLoadStyle || !mUpdatesEnabled) {
+  NS_ENSURE_TRUE(thisContent, NS_ERROR_FAILURE);
+
+  // When static documents are created, stylesheets are cloned manually.
+  if (mDontLoadStyle || !mUpdatesEnabled ||
+      thisContent->OwnerDoc()->IsStaticDocument()) {
     return NS_OK;
   }
 
-  NS_ENSURE_TRUE(thisContent, NS_ERROR_FAILURE);
-
   nsCOMPtr<nsIDocument> doc = thisContent->GetDocument();
 
   if (!doc || !doc->CSSLoader()->GetEnabled()) {