Move CrossThreadCopier from platform/ to wtf/

third_party/WebKit/Source/core/loader/ThreadableLoader.h

Index: third_party/WebKit/Source/core/loader/ThreadableLoader.h
diff --git a/third_party/WebKit/Source/core/loader/ThreadableLoader.h b/third_party/WebKit/Source/core/loader/ThreadableLoader.h
index 3d2b2d20aff83707451037ea35d51a712d6890a3..f0982fe68106ae5f4fb69ac9c25db69314751dd3 100644
--- a/third_party/WebKit/Source/core/loader/ThreadableLoader.h
+++ b/third_party/WebKit/Source/core/loader/ThreadableLoader.h
@@ -33,8 +33,8 @@
 
 #include "core/CoreExport.h"
 #include "core/fetch/ResourceLoaderOptions.h"
-#include "platform/CrossThreadCopier.h"
 #include "wtf/Allocator.h"
+#include "wtf/CrossThreadCopier.h"
 #include "wtf/Noncopyable.h"
 #include <memory>
 
@@ -106,15 +106,23 @@ struct CrossThreadThreadableLoaderOptionsData {
     unsigned long timeoutMilliseconds;
 };
 
+} // namespace blink
+
+namespace WTF {
+
 template <>
-struct CrossThreadCopier<ThreadableLoaderOptions> {
-    typedef CrossThreadThreadableLoaderOptionsData Type;
-    static Type copy(const ThreadableLoaderOptions& options)
+struct CrossThreadCopier<blink::ThreadableLoaderOptions> {
+    typedef blink::CrossThreadThreadableLoaderOptionsData Type;
+    static Type copy(const blink::ThreadableLoaderOptions& options)
     {
-        return CrossThreadThreadableLoaderOptionsData(options);
+        return blink::CrossThreadThreadableLoaderOptionsData(options);
     }
 };
 
+} // namespace WTF
+
+namespace blink {
+
 // Useful for doing loader operations from any thread (not threadsafe,
 // just able to run on threads other than the main thread).
 //