Remove obviously unneeded forward declarations from headers under src/{app,base,net}.

app/l10n_util.h

-// Copyright (c) 2006-2008 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.
 
 // This file contains utility functions for dealing with localized
 // content.
 
 #ifndef APP_L10N_UTIL_H_
 #define APP_L10N_UTIL_H_
 #pragma once
 
 #include <algorithm>
 #include <functional>
 #include <string>
 #include <vector>
 
 #include "build/build_config.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/scoped_ptr.h"
 #include "base/string16.h"
 #include "base/string_util.h"
 
 #if defined(OS_MACOSX)
 #include "app/l10n_util_mac.h"
 #endif  // OS_MACOSX
 
-class PrefService;
-
 namespace l10n_util {
 
 // This method is responsible for determining the locale as defined below. In
 // nearly all cases you shouldn't call this, rather use GetApplicationLocale
 // defined on browser_process.
 //
 // Returns the locale used by the Application.  First we use the value from the
 // command line (--lang), second we try the value in the prefs file (passed in
 // as |pref_locale|), finally, we fall back on the system locale. We only return
 // a value if there's a corresponding resource DLL for the locale.  Otherwise,
@@ skipping 146 matching lines @@
 const std::vector<std::string>& GetAvailableLocales();
 
 // Returns a vector of locale codes usable for accept-languages.
 void GetAcceptLanguagesForLocale(const std::string& display_locale,
                                  std::vector<std::string>* locale_codes);
 
 
 }  // namespace l10n_util
 
 #endif  // APP_L10N_UTIL_H_