Clean up forward declarations in Source/modules

Source/modules/webdatabase/DatabaseTracker.h

 /*
  * Copyright (C) 2007, 2008, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 23 matching lines @@
 #include "wtf/HashMap.h"
 #include "wtf/HashSet.h"
 #include "wtf/ThreadingPrimitives.h"
 #include "wtf/text/StringHash.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class Database;
 class DatabaseContext;
-class OriginLock;
 class SecurityOrigin;
 
 class DatabaseTracker {
     WTF_MAKE_NONCOPYABLE(DatabaseTracker); WTF_MAKE_FAST_ALLOCATED;
 public:
     static DatabaseTracker& tracker();
     // This singleton will potentially be used from multiple worker threads and the page's context thread simultaneously.  To keep this safe, it's
     // currently using 4 locks.  In order to avoid deadlock when taking multiple locks, you must take them in the correct order:
     // m_databaseGuard before quotaManager if both locks are needed.
     // m_openDatabaseMapGuard before quotaManager if both locks are needed.
@@ skipping 26 matching lines @@
     Mutex m_openDatabaseMapGuard;
     // This map contains raw pointers to a garbage-collected class. We can't
     // make this traceable because it is updated by multiple database threads.
     GC_PLUGIN_IGNORE("crbug.com/417990")
     mutable OwnPtr<DatabaseOriginMap> m_openDatabaseMap;
 };
 
 } // namespace blink
 
 #endif // DatabaseTracker_h