Allow the bootstrap binary of GN (the one in TEMPDIR) to build and run on FreeBSD.

tools/gn/escape.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <ostream>
+
 #include "tools/gn/escape.h"
 
 #include "base/containers/stack_container.h"
 
 namespace {
 
 template<typename DestString>
 void EscapeStringToString(const base::StringPiece& str,
                           const EscapeOptions& options,
                           DestString* dest,
@@ skipping 66 matching lines @@
 void EscapeStringToStream(std::ostream& out,
                           const base::StringPiece& str,
                           const EscapeOptions& options) {
   // Escape to a stack buffer and then write out to the stream.
   base::StackVector<char, 256> result;
   result->reserve(str.size() + 4);  // Guess we'll add a couple of extra chars.
   EscapeStringToString(str, options, &result.container(), NULL);
   if (!result->empty())
     out.write(result->data(), result->size());
 }