Componentize kBug464926CrashKey into crash_keys.

components/crash_keys/crash_keys.h

 // Copyright 2015 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_CRASH_KEYS_CRASH_KEYS_H_
 #define COMPONENTS_CRASH_KEYS_CRASH_KEYS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 40 matching lines @@
 // The product release/distribution channel.
 extern const char kChannel[];
 
 // The total number of experiments the instance has.
 extern const char kNumVariations[];
 
 // The experiments chunk. Hashed experiment names separated by |,|. This is
 // typically set by SetExperimentList.
 extern const char kVariations[];
 
+// Used to help investigate bug 464926.
+extern const char kBug464926CrashKey[];
+
 #if defined(OS_MACOSX)
 namespace mac {
 
 // Records Cocoa zombie/used-after-freed objects that resulted in a
 // deliberate crash.
 extern const char kZombie[];
 extern const char kZombieTrace[];
 
 }  // namespace mac
 #endif
 
 }  // namespace crash_keys
 
 #endif  // COMPONENTS_CRASH_KEYS_CRASH_KEYS_H_