Pass implementation object to supplemental classes by reference

Source/modules/filesystem/DraggedIsolatedFileSystem.cpp

 /*
  * Copyright (C) 2012 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 28 matching lines @@
 
 namespace WebCore {
 
 DraggedIsolatedFileSystem::~DraggedIsolatedFileSystem()
 {
 }
 
 DOMFileSystem* DraggedIsolatedFileSystem::getDOMFileSystem(ExecutionContext* executionContext)
 {
     ASSERT(!m_filesystemId.isEmpty());
-    if (!m_filesystem) {
-        ASSERT(executionContext);
+    if (!m_filesystem)
         m_filesystem = DOMFileSystem::createIsolatedFileSystem(executionContext, m_filesystemId);
-    }
     return m_filesystem.get();
 }
 
 // static
 const char* DraggedIsolatedFileSystem::supplementName()
 {
     ASSERT(isMainThread());
     return "DraggedIsolatedFileSystem";
 }
 
 DraggedIsolatedFileSystem::DraggedIsolatedFileSystem(const String& filesystemId)
     : m_filesystemId(filesystemId)
 {
 }
 
 } // namespace WebCore