Turn components/crash into a layered component.

components/crash/content/app/crash_keys_win.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_CRASH_CONTENT_APP_CRASH_KEYS_WIN_H_
+#define COMPONENTS_CRASH_CONTENT_APP_CRASH_KEYS_WIN_H_
+
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/synchronization/lock.h"
 #include "breakpad/src/client/windows/common/ipc_protocol.h"
 #include "breakpad/src/client/windows/handler/exception_handler.h"
 
 
@@ skipping 58 matching lines @@
   // in custom_entries_.
   DynamicEntriesMap dynamic_entries_;  // Under lock_.
 
   // Stores the sole instance of this class allowed per process.
   static CrashKeysWin* keeper_;
 
   DISALLOW_COPY_AND_ASSIGN(CrashKeysWin);
 };
 
 }  // namespace breakpad
+
+#endif  // COMPONENTS_CRASH_CONTENT_APP_CRASH_KEYS_WIN_H_