Mojo: Move system embedder API files to mojo/system/embedder.

mojo/common/test/multiprocess_test_base_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 "mojo/common/test/multiprocess_test_base.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
-#include "mojo/system/scoped_platform_handle.h"
+#include "mojo/system/embedder/scoped_platform_handle.h"
 
 #if defined(OS_POSIX)
 #include <fcntl.h>
 #include <unistd.h>
 
 #include "base/posix/eintr_wrapper.h"
 #endif
 
 namespace mojo {
 namespace {
@@ skipping 78 matching lines @@
   CHECK_EQ(write_size, 1);
 
   // And return it, incremented again.
   c++;
   return static_cast<int>(c);
 }
 #endif  // defined(OS_POSIX)
 
 }  // namespace
 }  // namespace mojo