Mojo: Move mojo/public/system/core_cpp.h to mojo/cpp/public/system/core.h.

mojo/public/tests/test_utils.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 "mojo/public/tests/test_utils.h"
 
-#include "mojo/public/system/core_cpp.h"
+#include "mojo/public/cpp/system/core.h"
 #include "mojo/public/tests/test_support.h"
 
 namespace mojo {
 namespace test {
 
 bool WriteTextMessage(const MessagePipeHandle& handle,
                       const std::string& text) {
   MojoResult rv = WriteMessageRaw(handle,
                                   text.data(),
                                   static_cast<uint32_t>(text.size()),
@@ skipping 64 matching lines @@
     end_time = GetTimeTicksNow();
   } while (end_time - start_time < kPerftestTimeMicroseconds);
 
   MojoTestSupportLogPerfResult(test_name,
                                1000000.0 * iterations / (end_time - start_time),
                                "iterations/second");
 }
 
 }  // namespace test
 }  // namespace mojo