Make PlatformFileForTransit its own class on Windows.

ipc/ipc_message_utils.cc

Index: ipc/ipc_message_utils.cc
diff --git a/ipc/ipc_message_utils.cc b/ipc/ipc_message_utils.cc
index db36c0fe7a62622fd0b7e4489c2bfdfd26f4a2f7..68f07f8795f480a6faa9dfb94695ef2dcffe78cf 100644
--- a/ipc/ipc_message_utils.cc
+++ b/ipc/ipc_message_utils.cc
@@ -35,6 +35,7 @@
 #if defined(OS_WIN)
 #include <tchar.h>
 #include "ipc/handle_win.h"
+#include "ipc/ipc_platform_file.h"
 #endif
 
 namespace IPC {
@@ -842,6 +843,35 @@ void ParamTraits<base::SharedMemoryHandle>::Log(const param_type& p,
 }
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
+#if defined(OS_WIN)
+void ParamTraits<PlatformFileForTransit>::GetSize(base::PickleSizer* s,
+                                                  const param_type& p) {
+  GetParamSize(s, p.GetHandle());
+}
+
+void ParamTraits<PlatformFileForTransit>::Write(base::Pickle* m,
+                                                const param_type& p) {
+  HandleWin handle_win(p.GetHandle(), HandleWin::DUPLICATE);
+  ParamTraits<HandleWin>::Write(m, handle_win);
+  ::CloseHandle(p.GetHandle());
+}
+
+bool ParamTraits<PlatformFileForTransit>::Read(const base::Pickle* m,
+                                               base::PickleIterator* iter,
+                                               param_type* r) {
+  HandleWin handle_win;
+  if (!ParamTraits<HandleWin>::Read(m, iter, &handle_win))
+    return false;
+  *r = PlatformFileForTransit(handle_win.get_handle());
+  return true;
+}
+
+void ParamTraits<PlatformFileForTransit>::Log(const param_type& p,
+                                              std::string* l) {
+  LogParam(p.GetHandle(), l);
+}
+#endif  // defined(OS_WIN)
+
 void ParamTraits<base::FilePath>::GetSize(base::PickleSizer* sizer,
                                           const param_type& p) {
   p.GetSizeForPickle(sizer);