Make BindStateBase constructor out-of-line

base/callback_internal.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains utility functions and classes that help the
 // implementation, and management of the Callback objects.
 
 #ifndef BASE_CALLBACK_INTERNAL_H_
 #define BASE_CALLBACK_INTERNAL_H_
 
@@ skipping 12 matching lines @@
 // class can use to represent a function object with bound arguments.  It
 // behaves as an existential type that is used by a corresponding
 // DoInvoke function to perform the function execution.  This allows
 // us to shield the Callback class from the types of the bound argument via
 // "type erasure."
 // At the base level, the only task is to add reference counting data. Don't use
 // RefCountedThreadSafe since it requires the destructor to be a virtual method.
 // Creating a vtable for every BindState template instantiation results in a lot
 // of bloat. Its only task is to call the destructor which can be done with a
 // function pointer.
-class BindStateBase {
+class BASE_EXPORT BindStateBase {
  public:
   using InvokeFuncStorage = void(*)();
 
  protected:
   BindStateBase(InvokeFuncStorage polymorphic_invoke,
-                void (*destructor)(BindStateBase*))
-      : polymorphic_invoke_(polymorphic_invoke),
-        ref_count_(0), destructor_(destructor) {}
+                void (*destructor)(BindStateBase*));
   ~BindStateBase() = default;
 
  private:
   friend class scoped_refptr<BindStateBase>;
   template <CopyMode copy_mode>
   friend class CallbackBase;
 
   void AddRef();
   void Release();
 
@@ skipping 65 matching lines @@
   ~CallbackBase() {}
 };
 
 extern template class CallbackBase<CopyMode::MoveOnly>;
 extern template class CallbackBase<CopyMode::Copyable>;
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_CALLBACK_INTERNAL_H_