FBTF: Remove "obviously" unneeded standard C++ library #includes.

chrome/browser/renderer_host/render_process_host.h

Index: chrome/browser/renderer_host/render_process_host.h
diff --git a/chrome/browser/renderer_host/render_process_host.h b/chrome/browser/renderer_host/render_process_host.h
index 45b643f2e1eb6d6100e7af749643395c2cafc58b..f2b26fb16fc4ac586a053ebe68b013d83b95f2d9 100644
--- a/chrome/browser/renderer_host/render_process_host.h
+++ b/chrome/browser/renderer_host/render_process_host.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -7,7 +7,6 @@
 #pragma once
 
 #include <set>
-#include <string>
 
 #include "app/surface/transport_dib.h"
 #include "base/id_map.h"