Do Perfect Forwarding from base::Bind to BindState storage

base/bind_internal.h

Index: base/bind_internal.h
diff --git a/base/bind_internal.h b/base/bind_internal.h
index ac7cd0098787b97ba8d14d35bf068311fade086d..ce6b5d67c6e365e40fb707de03f926d2d1b0129d 100644
--- a/base/bind_internal.h
+++ b/base/bind_internal.h
@@ -104,7 +104,8 @@ template <bool is_method, typename... Args>
 struct BindsArrayToFirstArg : false_type {};
 
 template <typename T, typename... Args>
-struct BindsArrayToFirstArg<true, T, Args...> : is_array<T> {};
+struct BindsArrayToFirstArg<true, T, Args...>
+    : is_array<typename std::remove_reference<T>::type> {};
 
 // HasRefCountedParamAsRawPtr is the same to HasRefCountedTypeAsRawPtr except
 // when |is_method| is true HasRefCountedParamAsRawPtr skips the first argument.
@@ -401,11 +402,12 @@ struct BindState<Runnable, R(Args...), BoundArgs...> final
                               InvokeHelperType, UnboundForwardRunType>;
   using UnboundRunType = MakeFunctionType<R, UnboundArgs>;
 
-  BindState(const Runnable& runnable, const BoundArgs&... bound_args)
+  template <typename... ForwardArgs>
+  BindState(const Runnable& runnable, ForwardArgs&&... bound_args)

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

Just as a quick sanity check.. does this have a visible effect on binary size?

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

Good point. Yes, this increases the stripped binary size by 8kB on Linux.
This tends to be inlined into the caller...

       : BindStateBase(&Destroy),
         runnable_(runnable),
         ref_(bound_args...),
-        bound_args_(bound_args...) {}
+        bound_args_(std::forward<ForwardArgs>(bound_args)...) {}
 
   RunnableType runnable_;
   MaybeScopedRefPtr<HasIsMethodTag<Runnable>::value, BoundArgs...> ref_;