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

mojo/edk/platform/platform_handle.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/edk/platform/platform_handle.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <unistd.h>
+
+namespace mojo {
+namespace platform {
+
+void PlatformHandle::CloseIfNecessary() {
+  if (!is_valid())
+    return;
+
+  if (close(fd) != 0) {
+    // The possible errors are EBADF (which is very bad -- it indicates a bug in
+    // our code), EINTR, or EIO. On EINTR, don't retry |close()| (this is the
+    // correct behavior on Linux, and the only safe thing to do on Mac: see,
+    // e.g., http://crbug.com/269623). EIO is sad (it indicates potential data
+    // loss), but again there's nothing more to do.
+    assert(errno == EINTR || errno == EIO);
+  }
+  fd = -1;
+}
+
+}  // namespace embedder
+}  // namespace mojo