diff --git a/base/files/file_util_proxy.cc b/base/files/file_util_proxy.cc
index 5eb9fe5..721f671 100644
--- a/base/files/file_util_proxy.cc
+++ b/base/files/file_util_proxy.cc
@@ -22,6 +22,7 @@
   callback.Run(value ? PLATFORM_FILE_OK : PLATFORM_FILE_ERROR_FAILED);
 }
 
+#if !defined(OS_NACL)
 // Helper classes or routines for individual methods.
 class CreateOrOpenHelper {
  public:
@@ -100,12 +101,14 @@
   PlatformFileError error_;
   DISALLOW_COPY_AND_ASSIGN(CreateTemporaryHelper);
 };
+#endif  // !defined(OS_NACL)
 
 class GetFileInfoHelper {
  public:
   GetFileInfoHelper()
       : error_(PLATFORM_FILE_OK) {}
 
+#if !defined(OS_NACL)
   void RunWorkForFilePath(const FilePath& file_path) {
     if (!PathExists(file_path)) {
       error_ = PLATFORM_FILE_ERROR_NOT_FOUND;
@@ -114,6 +117,7 @@
     if (!file_util::GetFileInfo(file_path, &file_info_))
       error_ = PLATFORM_FILE_ERROR_FAILED;
   }
+#endif  // !defined(OS_NACL)
 
   void RunWorkForPlatformFile(PlatformFile file) {
     if (!GetPlatformFileInfo(file, &file_info_))
@@ -187,7 +191,7 @@
   DISALLOW_COPY_AND_ASSIGN(WriteHelper);
 };
 
-
+#if !defined(OS_NACL)
 PlatformFileError CreateOrOpenAdapter(
     const FilePath& file_path, int file_flags,
     PlatformFile* file_handle, bool* created) {
@@ -201,6 +205,7 @@
   *file_handle = CreatePlatformFile(file_path, file_flags, created, &error);
   return error;
 }
+#endif  // !defined(OS_NACL)
 
 PlatformFileError CloseAdapter(PlatformFile file_handle) {
   if (!ClosePlatformFile(file_handle)) {
@@ -209,6 +214,7 @@
   return PLATFORM_FILE_OK;
 }
 
+#if !defined(OS_NACL)
 PlatformFileError DeleteAdapter(const FilePath& file_path, bool recursive) {
   if (!PathExists(file_path)) {
     return PLATFORM_FILE_ERROR_NOT_FOUND;
@@ -221,9 +227,11 @@
   }
   return PLATFORM_FILE_OK;
 }
+#endif  // !defined(OS_NACL)
 
 }  // namespace
 
+#if !defined(OS_NACL)
 // static
 bool FileUtilProxy::CreateOrOpen(
     TaskRunner* task_runner,
@@ -248,6 +256,7 @@
            additional_file_flags),
       Bind(&CreateTemporaryHelper::Reply, Owned(helper), callback));
 }
+#endif  // !defined(OS_NACL)
 
 // static
 bool FileUtilProxy::Close(
@@ -260,6 +269,7 @@
       file_handle, callback);
 }
 
+#if !defined(OS_NACL)
 // Retrieves the information about a file. It is invalid to pass NULL for the
 // callback.
 bool FileUtilProxy::GetFileInfo(
@@ -273,6 +283,7 @@
            Unretained(helper), file_path),
       Bind(&GetFileInfoHelper::Reply, Owned(helper), callback));
 }
+#endif  // !defined(OS_NACL)
 
 // static
 bool FileUtilProxy::GetFileInfoFromPlatformFile(
@@ -287,6 +298,7 @@
       Bind(&GetFileInfoHelper::Reply, Owned(helper), callback));
 }
 
+#if !defined(OS_NACL)
 // static
 bool FileUtilProxy::Delete(TaskRunner* task_runner,
                            const FilePath& file_path,
@@ -308,6 +320,7 @@
       Bind(&DeleteAdapter, file_path, true /* recursive */),
       callback);
 }
+#endif  // !defined(OS_NACL)
 
 // static
 bool FileUtilProxy::Read(
@@ -344,6 +357,7 @@
       Bind(&WriteHelper::Reply, Owned(helper), callback));
 }
 
+#if !defined(OS_NACL)
 // static
 bool FileUtilProxy::Touch(
     TaskRunner* task_runner,
@@ -412,6 +426,7 @@
       Bind(&CreateOrOpenHelper::RunWork, Unretained(helper), open_task),
       Bind(&CreateOrOpenHelper::Reply, Owned(helper), callback));
 }
+#endif  // !defined(OS_NACL)
 
 // static
 bool FileUtilProxy::RelayClose(