Cleanup: Remove unneeded forward declarations in chrome/installer.

chrome/installer/util/google_chrome_sxs_distribution.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
 #ifndef CHROME_INSTALLER_UTIL_GOOGLE_CHROME_SXS_DISTRIBUTION_H_
 #define CHROME_INSTALLER_UTIL_GOOGLE_CHROME_SXS_DISTRIBUTION_H_
 #pragma once
 
 #include "chrome/installer/util/browser_distribution.h"
 #include "chrome/installer/util/google_chrome_distribution.h"
 #include "chrome/installer/util/l10n_string_util.h"
 #include "chrome/installer/util/util_constants.h"
 
-namespace installer {
-class MasterPreferences;
-}
-
 // GoogleChromeSxSDistribution encapsulates properties of Google Chrome Sxs
 // distribution which can co-exist with other Google Chrome distributions.
 // Google Chrome Sxs distribution is installed to a different path, runs
 // alongside with normally installed Google Chrome, and is updated separately.
 // It is mainly used for developer preview and testing, and is disabled for
 // system level install and setting as default browser.
 class GoogleChromeSxSDistribution : public GoogleChromeDistribution {
  public:
   virtual std::wstring GetApplicationName() OVERRIDE;
   virtual std::wstring GetAppShortCutName() OVERRIDE;
   virtual std::wstring GetBrowserAppId() OVERRIDE;
   virtual std::wstring GetInstallSubDir() OVERRIDE;
   virtual std::wstring GetUninstallRegPath() OVERRIDE;
   virtual bool CanSetAsDefault() OVERRIDE;
   virtual int GetIconIndex() OVERRIDE;
   virtual bool GetChromeChannel(std::wstring* channel) OVERRIDE;
   // returns the channel name for GoogleChromeSxSDistribution
   static std::wstring ChannelName();
  private:
   friend class BrowserDistribution;
 
   // Disallow construction from non-friends.
   GoogleChromeSxSDistribution();
 };
 
 #endif  // CHROME_INSTALLER_UTIL_GOOGLE_CHROME_SXS_DISTRIBUTION_H_