EDK: Move {platform_handle,scoped_platform_handle}.* to //mojo/edk/platform.

mojo/edk/embedder/platform_handle_utils_posix.cc

 // Copyright 2014 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/edk/embedder/platform_handle_utils.h"
 
 #include <unistd.h>
 
 #include "base/logging.h"
 
+using mojo::platform::PlatformHandle;
+using mojo::platform::ScopedPlatformHandle;
+
 namespace mojo {
 namespace embedder {
 
 ScopedPlatformHandle DuplicatePlatformHandle(PlatformHandle platform_handle) {
   DCHECK(platform_handle.is_valid());
   // Note that |dup()| returns -1 on error (which is exactly the value we use
   // for invalid |PlatformHandle| FDs).
   return ScopedPlatformHandle(PlatformHandle(dup(platform_handle.fd)));
 }
 
 }  // namespace embedder
 }  // namespace mojo