Cleanup: Remove unneeded base/file_util.h includes in content.

content/browser/renderer_host/render_view_host_manager_browsertest.cc

Index: content/browser/renderer_host/render_view_host_manager_browsertest.cc
===================================================================
--- content/browser/renderer_host/render_view_host_manager_browsertest.cc	(revision 199525)
+++ content/browser/renderer_host/render_view_host_manager_browsertest.cc	(working copy)
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/memory/ref_counted.h"
 #include "base/path_service.h"
@@ -1050,6 +1049,7 @@
   size_t GetNumObservers() const {
     return observers_.size();
   }
+
  private:
   friend class RVHObserver;
   class RVHObserver : public RenderViewHostObserver {