Move WriteFile and WriteFileDescriptor from file_util to base namespace.

base/sync_socket_posix.cc

Index: base/sync_socket_posix.cc
diff --git a/base/sync_socket_posix.cc b/base/sync_socket_posix.cc
index 5bb893aae87319a80aeeabb83ba0aea23edca349..6d397ffa2ec991bbe288f2abad6e85e4c3b683ca 100644
--- a/base/sync_socket_posix.cc
+++ b/base/sync_socket_posix.cc
@@ -36,7 +36,7 @@ size_t SendHelper(SyncSocket::Handle handle,
   DCHECK_LE(length, kMaxMessageLength);
   DCHECK_NE(handle, SyncSocket::kInvalidHandle);
   const char* charbuffer = static_cast<const char*>(buffer);
-  const int len = file_util::WriteFileDescriptor(handle, charbuffer, length);
+  const int len = WriteFileDescriptor(handle, charbuffer, length);
   return len < 0 ? 0 : static_cast<size_t>(len);
 }