Component updater must enforce that the brand length is 4.

components/update_client/utils.h

 // Copyright 2014 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 COMPONENTS_UPDATE_CLIENT_UTILS_H_
 #define COMPONENTS_UPDATE_CLIENT_UTILS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 78 matching lines @@
 
 // Returns the component id of the |component|. The component id is in a
 // format similar with the format of an extension id.
 std::string GetCrxComponentID(const CrxComponent& component);
 
 // Returns true if the actual SHA-256 hash of the |filepath| matches the
 // |expected_hash|.
 bool VerifyFileHash256(const base::FilePath& filepath,
                        const std::string& expected_hash);
 
-// Returns true if the |brand| parameter matches ^([a-zA-Z]{4})?$ .
+// Returns true if the |brand| parameter matches ^[a-zA-Z]{4}?$ .
 bool IsValidBrand(const std::string& brand);
 
 // Returns true if the |ap| parameter matches ^[-+_=a-zA-Z0-9]{0,256}$ .
 bool IsValidAp(const std::string& ap);
 
 // Removes the unsecure urls in the |urls| parameter.
 void RemoveUnsecureUrls(std::vector<GURL>* urls);
 
 }  // namespace update_client
 
 #endif  // COMPONENTS_UPDATE_CLIENT_UTILS_H_