styleguide: Allow std::move for move semantics.

base/move.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.
 
 #ifndef BASE_MOVE_H_
 #define BASE_MOVE_H_
 
+#include <utility>
+
 #include "base/compiler_specific.h"
 
 // Macro with the boilerplate that makes a type move-only in C++03.
 //
 // USAGE
 //
 // This macro should be used instead of DISALLOW_COPY_AND_ASSIGN to create
 // a "move-only" type.  Unlike DISALLOW_COPY_AND_ASSIGN, this macro should be
 // the first line in a class declaration.
 //
@@ skipping 197 matching lines @@
   operator rvalue_type() { return rvalue_type(this); } \
   type Pass() WARN_UNUSED_RESULT { return type(rvalue_type(this)); } \
   typedef void MoveOnlyTypeForCPP03; \
  private:
 
 #define MOVE_ONLY_TYPE_WITH_MOVE_CONSTRUCTOR_FOR_CPP_03(type) \
  private: \
   type(const type&); \
   void operator=(const type&); \
  public: \
-  type&& Pass() WARN_UNUSED_RESULT { return static_cast<type&&>(*this); } \
+  type&& Pass() WARN_UNUSED_RESULT { return std::move(*this); } \
   typedef void MoveOnlyTypeForCPP03; \
  private:
 
 #define TYPE_WITH_MOVE_CONSTRUCTOR_FOR_CPP_03(type) \
  public: \
-  type&& Pass() WARN_UNUSED_RESULT { return static_cast<type&&>(*this); } \
+  type&& Pass() WARN_UNUSED_RESULT { return std::move(*this); } \
  private:
 
 #endif  // BASE_MOVE_H_