Update BaseBindRewriters to convert base::Bind to base::BindOnce

tools/clang/base_bind_rewriters/tests/callback.h

+// Copyright 2017 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.
+
+#include <utility>
+
+namespace base {
+namespace internal {
+
+enum class CopyMode { MoveOnly, Copyable };
+enum class RepeatMode { Once, Repeating };
+
+}  // namespace internal
+
+template <typename Signature,
+          internal::CopyMode copy_mode = internal::CopyMode::Copyable,
+          internal::RepeatMode repeat_mode = internal::RepeatMode::Repeating>
+class Callback;
+
+template <typename Signature>
+using OnceCallback = Callback<Signature,
+                              internal::CopyMode::MoveOnly,
+                              internal::RepeatMode::Once>;
+template <typename Signature>
+using RepeatingCallback = Callback<Signature,
+                                   internal::CopyMode::Copyable,
+                                   internal::RepeatMode::Repeating>;
+
+using Closure = Callback<void()>;
+using OnceClosure = OnceCallback<void()>;
+using RepeatingClosure = RepeatingCallback<void()>;
+
+namespace internal {
+
+template <typename From, typename To>
+struct IsCallbackConvertible : std::false_type {};
+
+template <typename Signature>
+struct IsCallbackConvertible<RepeatingCallback<Signature>,
+                             OnceCallback<Signature>> : std::true_type {};
+
+}  // namespace internal
+
+template <typename Signature, internal::CopyMode, internal::RepeatMode>
+class Callback {
+ public:
+  Callback() {}
+  Callback(const Callback&) {}
+  Callback(Callback&&) {}
+
+  template <typename OtherCallback,
+            typename = typename std::enable_if<
+                internal::IsCallbackConvertible<OtherCallback,
+                                                Callback>::value>::type>
+  Callback(OtherCallback other) {}
+};
+
+template <typename Functor, typename... Args>
+Callback<void()> Bind(Functor, Args&&...) {
+  return Callback<void()>();
+}
+
+template <typename Functor, typename... Args>
+OnceCallback<void()> BindOnce(Functor, Args&&...) {
+  return Callback<void()>();
+}
+
+}  // namespace base