Remove some PlatformFile uses from NaCl.

ipc/ipc_platform_file.cc

Index: ipc/ipc_platform_file.cc
diff --git a/ipc/ipc_platform_file.cc b/ipc/ipc_platform_file.cc
index 4a756ea678881c35a236a0161dcdbf06a4acc71d..826d03014ed752ee6ef3d9adb1ab39684c42c2c8 100644
--- a/ipc/ipc_platform_file.cc
+++ b/ipc/ipc_platform_file.cc
@@ -45,4 +45,9 @@ PlatformFileForTransit GetFileHandleForProcess(base::PlatformFile handle,
   return out_handle;
 }
 
+PlatformFileForTransit TakeFileHandleForProcess(base::File file,
+                                                base::ProcessHandle process) {
+  return GetFileHandleForProcess(file.TakePlatformFile(), process, true);
+}
+
 }  // namespace IPC