Replace threadSafeBind() + GCed pointers with CrossThreadPersistent

third_party/WebKit/Source/platform/CrossThreadCopier.cpp

Index: third_party/WebKit/Source/platform/CrossThreadCopier.cpp
diff --git a/third_party/WebKit/Source/platform/CrossThreadCopier.cpp b/third_party/WebKit/Source/platform/CrossThreadCopier.cpp
index 74eaa3d87cf295d0ada84e6715dc9956530c0ca0..f5b4c797c1371ebe635b3197d0232772656aead8 100644
--- a/third_party/WebKit/Source/platform/CrossThreadCopier.cpp
+++ b/third_party/WebKit/Source/platform/CrossThreadCopier.cpp
@@ -87,7 +87,7 @@ static_assert((std::is_same<
 
 
 // Add a generic specialization which will let's us verify that no other template matches.
-template<typename T> struct CrossThreadCopierBase<T, false, false, false> {
+template<typename T> struct CrossThreadCopierBase<T, false, false> {
     typedef int Type;
 };