Refactor SetOmahaExperimentLabel out of gcpai and into install_util.

chrome/installer/util/install_util.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.
 //
 // This file declares utility functions for the installer. The original reason
 // for putting these functions in installer\util library is so that we can
 // separate out the critical logic and write unit tests for it.
 
 #ifndef CHROME_INSTALLER_UTIL_INSTALL_UTIL_H_
 #define CHROME_INSTALLER_UTIL_INSTALL_UTIL_H_
@@ skipping 157 matching lines @@
   static int GetInstallReturnCode(installer::InstallStatus install_status);
 
   // Composes |program| and |arguments| into |command_line|.
   static void MakeUninstallCommand(const string16& program,
                                    const string16& arguments,
                                    CommandLine* command_line);
 
   // Returns a string in the form YYYYMMDD of the current date.
   static string16 GetCurrentDate();
 
+  // Sets |experiment_label| as the Omaha experiment label for the Chrome
+  // product registry entries for a given |registry_hive|.
+  static bool SetOmahaExperimentLabel(const string16& experiment_label,
+                                      HKEY registry_hive);
+
   // A predicate that compares the program portion of a command line with a
   // given file path.  First, the file paths are compared directly.  If they do
   // not match, the filesystem is consulted to determine if the paths reference
   // the same file.
   class ProgramCompare : public RegistryValuePredicate {
    public:
     explicit ProgramCompare(const FilePath& path_to_match);
     virtual ~ProgramCompare();
     virtual bool Evaluate(const string16& value) const OVERRIDE;
 
@@ skipping 10 matching lines @@
    private:
     DISALLOW_COPY_AND_ASSIGN(ProgramCompare);
   };  // class ProgramCompare
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InstallUtil);
 };
 
 
 #endif  // CHROME_INSTALLER_UTIL_INSTALL_UTIL_H_