Revert of Deletes mojo::Callback

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

 // Copyright 2013 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 <stdint.h>
 #include <utility>
 
 #include "base/bind.h"
-#include "base/callback.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/public/interfaces/bindings/tests/math_calculator.mojom.h"
 #include "mojo/public/interfaces/bindings/tests/sample_interfaces.mojom.h"
 #include "mojo/public/interfaces/bindings/tests/sample_service.mojom.h"
 #include "mojo/public/interfaces/bindings/tests/scoping.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace test {
 namespace {
 
-typedef base::Callback<void(double)> CalcCallback;
+typedef mojo::Callback<void(double)> CalcCallback;
 
 class MathCalculatorImpl : public math::Calculator {
  public:
   explicit MathCalculatorImpl(InterfaceRequest<math::Calculator> request)
       : total_(0.0), binding_(this, std::move(request)) {}
   ~MathCalculatorImpl() override {}
 
   void CloseMessagePipe() { binding_.Close(); }
 
   void WaitForIncomingMethodCall() { binding_.WaitForIncomingMethodCall(); }
@@ skipping 698 matching lines @@
   bool called = false;
   base::RunLoop loop;
   ptr->Ping(base::Bind(&SetFlagAndRunClosure, &called, loop.QuitClosure()));
   loop.Run();
   EXPECT_TRUE(called);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo