IPC::Message Refactoring: Move POSIX specific bits to PlatformFileAttachment

ipc/ipc_platform_file_attachment.cc

Index: ipc/ipc_platform_file_attachment.cc
diff --git a/ipc/ipc_platform_file_attachment.cc b/ipc/ipc_platform_file_attachment.cc
index 5430c6de6734ae29e8477d0b3964d0c8d83a66b5..f29a81fbe1d0ef87754dccba26df3def5485d40d 100644
--- a/ipc/ipc_platform_file_attachment.cc
+++ b/ipc/ipc_platform_file_attachment.cc
@@ -11,6 +11,10 @@ PlatformFileAttachment::PlatformFileAttachment(base::PlatformFile file)
     : file_(file) {
 }
 
+PlatformFileAttachment::PlatformFileAttachment(base::ScopedFD file)
+    : file_(file.get()), owning_(file.Pass()) {
+}
+
 PlatformFileAttachment::~PlatformFileAttachment() {
 }
 
@@ -18,6 +22,11 @@ MessageAttachment::Type PlatformFileAttachment::GetType() const {
   return TYPE_PLATFORM_FILE;
 }
 
+base::PlatformFile PlatformFileAttachment::TakePlatformFile() {
+  ignore_result(owning_.release());
+  return file_;
+}
+
 base::PlatformFile GetPlatformFile(
     scoped_refptr<MessageAttachment> attachment) {
   DCHECK_EQ(attachment->GetType(), MessageAttachment::TYPE_PLATFORM_FILE);