Replace typedef with using for Callback/Bind related files

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 55 matching lines @@
   bool is_null() const { return bind_state_.get() == NULL; }
 
   // Returns the Callback into an uninitialized state.
   void Reset();
 
  protected:
   // In C++, it is safe to cast function pointers to function pointers of
   // another type. It is not okay to use void*. We create a InvokeFuncStorage
   // that that can store our function pointer, and then cast it back to
   // the original type on usage.
-  typedef void(*InvokeFuncStorage)(void);
+  using InvokeFuncStorage = void(*)();
 
   // Returns true if this callback equals |other|. |other| may be null.
   bool Equals(const CallbackBase& other) const;
 
   // Allow initializing of |bind_state_| via the constructor to avoid default
   // initialization of the scoped_refptr.  We do not also initialize
   // |polymorphic_invoke_| here because doing a normal assignment in the
   // derived Callback templates makes for much nicer compiler errors.
   explicit CallbackBase(BindStateBase* bind_state);
 
@@ skipping 54 matching lines @@
 // break passing of C-string literals.
 template <typename T>
 struct CallbackParamTraits
     : std::conditional<IsMoveOnlyType<T>::value,
          CallbackParamTraitsForMoveOnlyType<T>,
          CallbackParamTraitsForNonMoveOnlyType<T>>::type {
 };
 
 template <typename T>
 struct CallbackParamTraitsForNonMoveOnlyType {
-  typedef const T& ForwardType;
-  typedef T StorageType;
+  using ForwardType = const T&;
+  using StorageType = T;
 };
 
 // The Storage should almost be impossible to trigger unless someone manually
 // specifies type of the bind parameters.  However, in case they do,
 // this will guard against us accidentally storing a reference parameter.
 //
 // The ForwardType should only be used for unbound arguments.
 template <typename T>
 struct CallbackParamTraitsForNonMoveOnlyType<T&> {
-  typedef T& ForwardType;
-  typedef T StorageType;
+  using ForwardType = T&;
+  using StorageType = T;
 };
 
 // Note that for array types, we implicitly add a const in the conversion. This
 // means that it is not possible to bind array arguments to functions that take
 // a non-const pointer. Trying to specialize the template based on a "const
 // T[n]" does not seem to match correctly, so we are stuck with this
 // restriction.
 template <typename T, size_t n>
 struct CallbackParamTraitsForNonMoveOnlyType<T[n]> {
-  typedef const T* ForwardType;
-  typedef const T* StorageType;
+  using ForwardType = const T*;
+  using StorageType = const T*;
 };
 
 // See comment for CallbackParamTraits<T[n]>.
 template <typename T>
 struct CallbackParamTraitsForNonMoveOnlyType<T[]> {
-  typedef const T* ForwardType;
-  typedef const T* StorageType;
+  using ForwardType = const T*;
+  using StorageType = const T*;
 };
 
 // Parameter traits for movable-but-not-copyable scopers.
 //
 // Callback<>/Bind() understands movable-but-not-copyable semantics where
 // the type cannot be copied but can still have its state destructively
 // transferred (aka. moved) to another instance of the same type by calling a
 // helper function.  When used with Bind(), this signifies transferal of the
 // object's state to the target function.
 //
 // For these types, the ForwardType must not be a const reference, or a
 // reference.  A const reference is inappropriate, and would break const
 // correctness, because we are implementing a destructive move.  A non-const
 // reference cannot be used with temporaries which means the result of a
 // function or a cast would not be usable with Callback<> or Bind().
 template <typename T>
 struct CallbackParamTraitsForMoveOnlyType {
-  typedef T ForwardType;
-  typedef T StorageType;
+  using ForwardType = T;
+  using StorageType = T;
 };
 
 // CallbackForward() is a very limited simulation of C++11's std::forward()
 // used by the Callback/Bind system for a set of movable-but-not-copyable
 // types.  It is needed because forwarding a movable-but-not-copyable
 // argument to another function requires us to invoke the proper move
 // operator to create a rvalue version of the type.  The supported types are
 // whitelisted below as overloads of the CallbackForward() function. The
 // default template compiles out to be a no-op.
 //
@@ skipping 14 matching lines @@
 template <typename T>
 typename std::enable_if<IsMoveOnlyType<T>::value, T>::type CallbackForward(
     T& t) {
   return std::move(t);
 }
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_CALLBACK_INTERNAL_H_