Pass implementation object to supplemental classes by reference

Source/web/DatabaseClientImpl.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 45 matching lines @@
     ASSERT(executionContext->isContextThread());
     ASSERT(executionContext->isDocument() || executionContext->isWorkerGlobalScope());
     if (executionContext->isDocument()) {
         Document* document = toDocument(executionContext);
         WebFrameImpl* webFrame = WebFrameImpl::fromFrame(document->frame());
         if (!webFrame)
             return false;
         if (webFrame->permissionClient())
             return webFrame->permissionClient()->allowDatabase(webFrame, name, displayName, estimatedSize);
     } else {
-        WorkerGlobalScope* workerGlobalScope = toWorkerGlobalScope(executionContext);
+        WorkerGlobalScope& workerGlobalScope = *toWorkerGlobalScope(executionContext);
         return WorkerPermissionClient::from(workerGlobalScope)->allowDatabase(name, displayName, estimatedSize);
     }
     return true;
 }
 
 DatabaseClientImpl::DatabaseClientImpl()
 {
 }
 
 } // namespace blink