Add a method to read the Omaha experiment_labels value.

chrome/installer/util/google_update_settings.h

 // Copyright (c) 2012 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_UPDATE_SETTINGS_H_
 #define CHROME_INSTALLER_UTIL_GOOGLE_UPDATE_SETTINGS_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 239 matching lines @@
 
   // Sets |experiment_labels| as the Omaha experiment_labels value in the
   // ClientState key for this Chrome product, if appropriate. If
   // |experiment_labels| is empty, this will delete the value instead. This will
   // return true if the label was successfully set (or deleted), false otherwise
   // (even if the label does not need to be set for this particular distribution
   // type).
   static bool SetExperimentLabels(bool system_install,
                                   const string16& experiment_labels);
 
+  // Reads the Omaha experiment_labels value in the ClientState key for this
+  // Chrome product and writes it into |experiment_labels|. If this distribution
+  // of Chrome does not set the experiment_labels value, this will do nothing to
+  // |experiment_labels|. This will return true if the label was successfully
+  // read.
+  static bool ReadExperimentLabels(bool system_install,
+                                   string16* experiment_labels);
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(GoogleUpdateSettings);
 };
 
 #endif  // CHROME_INSTALLER_UTIL_GOOGLE_UPDATE_SETTINGS_H_