Revert of Use a class instead of several separate globals in crash_logging.cc.

base/debug/crash_logging.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 BASE_DEBUG_CRASH_LOGGING_H_
 #define BASE_DEBUG_CRASH_LOGGING_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 77 matching lines @@
     SetCrashKeyValueFuncT set_key_func,
     ClearCrashKeyValueFuncT clear_key_func);
 
 // Helper function that breaks up a value according to the parameters
 // specified by the crash key object.
 BASE_EXPORT std::vector<std::string> ChunkCrashKeyValue(
     const CrashKey& crash_key,
     const base::StringPiece& value,
     size_t chunk_max_length);
 
+// Resets the crash key system so it can be reinitialized. For testing only.
+BASE_EXPORT void ResetCrashLoggingForTesting();
+
 }  // namespace debug
 }  // namespace base
 
 #endif  // BASE_DEBUG_CRASH_LOGGING_H_