Do Perfect Forwarding from base::Bind to BindState storage

base/callback_internal.h

Index: base/callback_internal.h
diff --git a/base/callback_internal.h b/base/callback_internal.h
index e4e538ff15c2d0dfe239bc5d8b17fe411c59926e..79b0895fb6a7fa88e644379b72c58158f59ac4a9 100644
--- a/base/callback_internal.h
+++ b/base/callback_internal.h
@@ -149,7 +149,6 @@ struct CallbackParamTraits
 template <typename T>
 struct CallbackParamTraitsForNonMoveOnlyType {
   using ForwardType = const T&;
-  using StorageType = T;
 };
 
 // The Storage should almost be impossible to trigger unless someone manually
@@ -160,7 +159,6 @@ struct CallbackParamTraitsForNonMoveOnlyType {
 template <typename T>
 struct CallbackParamTraitsForNonMoveOnlyType<T&> {

[danakj, 2016/01/28 23:01:00]

Do we still need this specialization?

[tzik, 2016/02/01 15:00:16]

Done.

   using ForwardType = T&;
-  using StorageType = T;
 };
 
 // Note that for array types, we implicitly add a const in the conversion. This
@@ -171,14 +169,12 @@ struct CallbackParamTraitsForNonMoveOnlyType<T&> {
 template <typename T, size_t n>
 struct CallbackParamTraitsForNonMoveOnlyType<T[n]> {
   using ForwardType = const T*;
-  using StorageType = const T*;
 };
 
 // See comment for CallbackParamTraits<T[n]>.
 template <typename T>
 struct CallbackParamTraitsForNonMoveOnlyType<T[]> {
   using ForwardType = const T*;
-  using StorageType = const T*;
 };
 
 // Parameter traits for movable-but-not-copyable scopers.
@@ -197,7 +193,6 @@ struct CallbackParamTraitsForNonMoveOnlyType<T[]> {
 template <typename T>
 struct CallbackParamTraitsForMoveOnlyType {
   using ForwardType = T;
-  using StorageType = T;
 };
 
 // CallbackForward() is a very limited simulation of C++11's std::forward()