[cros] RLZ tracking can be turned off via a flag file.

chrome/browser/google/google_util_chromeos.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_BROWSER_GOOGLE_GOOGLE_UTIL_CHROMEOS_H_
 #define CHROME_BROWSER_GOOGLE_GOOGLE_UTIL_CHROMEOS_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 
 namespace google_util {
 namespace chromeos {
 
 // Returns the brand code stored in Local State that has been assigned to a
 // partner. Returns empty string if the information is not available.
 std::string GetBrand();
 
+// Clears brand code for the current session (not persisted through browser
+// restart). Future calls to GetBrand() will return an empty string.
+void ClearBrandForCurrentSession();
+
 // Reads the brand code from a board-specific file and stores it to Local State.
 // |callback| is invoked on the calling thread after that.
 void SetBrandFromFile(const base::Closure& callback);
 
 }  // namespace chromeos
 }  // namespace google_util
 
 #endif  // CHROME_BROWSER_GOOGLE_GOOGLE_UTIL_CHROMEOS_H_