DevTools: use target-based model accessors only.

Source/devtools/front_end/sdk/Database.js

 /*
  * Copyright (C) 2007, 2008 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 198 matching lines @@
     addDatabase: function(payload)
     {
         this._model._addDatabase(new WebInspector.Database(
             this._model,
             payload.id,
             payload.domain,
             payload.name,
             payload.version));
     }
 }
-
-/**
- * @type {!WebInspector.DatabaseModel}
- */
-WebInspector.databaseModel;