Revert 114494 - Remove BindStateHolder and have Bind() return a Callback<> object directly.

base/callback_internal.cc

Index: base/callback_internal.cc
===================================================================
--- base/callback_internal.cc	(revision 114494)
+++ base/callback_internal.cc	(working copy)
@@ -4,8 +4,6 @@
 
 #include "base/callback_internal.h"
 
-#include "base/logging.h"
-
 namespace base {
 namespace internal {
 
@@ -23,10 +21,12 @@
          polymorphic_invoke_ == other.polymorphic_invoke_;
 }
 
-CallbackBase::CallbackBase(BindStateBase* bind_state)
-    : bind_state_(bind_state),
-      polymorphic_invoke_(NULL) {
-  DCHECK(!bind_state_ || bind_state_->HasOneRef());
+CallbackBase::CallbackBase(InvokeFuncStorage polymorphic_invoke,
+                           scoped_refptr<BindStateBase>* bind_state)
+    : polymorphic_invoke_(polymorphic_invoke) {
+  if (bind_state) {
+    bind_state_.swap(*bind_state);
+  }
 }
 
 CallbackBase::~CallbackBase() {