Revert of Deletes mojo::Callback

mojo/public/cpp/bindings/tests/associated_interface_unittest.cc

 // Copyright 2015 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 <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
-#include "base/callback.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "mojo/public/cpp/bindings/associated_group.h"
 #include "mojo/public/cpp/bindings/associated_interface_ptr.h"
 #include "mojo/public/cpp/bindings/associated_interface_ptr_info.h"
 #include "mojo/public/cpp/bindings/associated_interface_request.h"
 #include "mojo/public/cpp/bindings/binding.h"
@@ skipping 19 matching lines @@
     notify_send_method_called_ = callback;
   }
 
   void Echo(int32_t value, const EchoCallback& callback) override {
     callback.Run(value);
   }
   void Send(int32_t value) override { notify_send_method_called_.Run(value); }
 
   AssociatedBinding<IntegerSender>* binding() { return &binding_; }
 
-  void set_connection_error_handler(const base::Closure& handler) {
+  void set_connection_error_handler(const Closure& handler) {
     binding_.set_connection_error_handler(handler);
   }
 
  private:
   AssociatedBinding<IntegerSender> binding_;
   base::Callback<void(int32_t)> notify_send_method_called_;
 };
 
 class IntegerSenderConnectionImpl : public IntegerSenderConnection {
  public:
@@ skipping 522 matching lines @@
 
   // The previous wait has dispatched the GetSender request message, therefore
   // an associated interface has been set up on the pipe. It is not allowed to
   // wait or pause.
   EXPECT_TRUE(connection.binding()->HasAssociatedInterfaces());
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo