Refactor ThreadableLoaderOptions for readability

Source/platform/CrossThreadCopier.h

Index: Source/platform/CrossThreadCopier.h
diff --git a/Source/platform/CrossThreadCopier.h b/Source/platform/CrossThreadCopier.h
index 0adbf860d1a5026e9614682c7c7555deb1022c9c..7c0e48c4fb73243adf4adda8645dee495d0ac9ab 100644
--- a/Source/platform/CrossThreadCopier.h
+++ b/Source/platform/CrossThreadCopier.h
@@ -51,6 +51,7 @@ namespace WebCore {
     struct CrossThreadResourceResponseData;
     struct CrossThreadResourceRequestData;
     struct ThreadableLoaderOptions;
+    struct ResourceLoaderOptions;
 
     template<typename T> struct CrossThreadCopierPassThrough {
         typedef T Type;
@@ -71,6 +72,9 @@ namespace WebCore {
     template<> struct CrossThreadCopierBase<false, false, ThreadableLoaderOptions> : public CrossThreadCopierPassThrough<ThreadableLoaderOptions> {
     };
 
+    template<> struct CrossThreadCopierBase<false, false, ResourceLoaderOptions> : public CrossThreadCopierPassThrough<ResourceLoaderOptions> {
+    };
+
     template<> struct CrossThreadCopierBase<false, false, IntRect> : public CrossThreadCopierPassThrough<IntRect> {
     };