Move GUID utils to src/chrome/common.

chrome/common/guid.h

 // Copyright (c) 2010 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_GUID_H_
-#define CHROME_BROWSER_GUID_H_
+#ifndef CHROME_COMMON_GUID_H_
+#define CHROME_COMMON_GUID_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "build/build_config.h"
 
 namespace guid {
 
 // Generate a 128-bit random GUID of the form: "%08X-%04X-%04X-%04X-%012llX".
 // If GUID generation fails an empty string is returned.
 // The POSIX implementation uses psuedo random number generation to create
 // the GUID.  The Windows implementation uses system services.
 std::string GenerateGUID();
 
 // Returns true if the input string conforms to the GUID format.
 bool IsValidGUID(const std::string& guid);
 
 #if defined(OS_POSIX)
 // For unit testing purposes only.  Do not use outside of tests.
 std::string RandomDataToGUIDString(const uint64 bytes[2]);
 #endif
 
 }  // namespace guid
 
-#endif  // CHROME_BROWSER_GUID_H_
+#endif  // CHROME_COMMON_GUID_H_