Revert of Prefer using ContextClient over ContextLifecycleObserver

third_party/WebKit/Source/modules/filesystem/DOMFileSystem.cpp

 /*
  * Copyright (C) 2010 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 74 matching lines @@
   return DOMFileSystem::create(context, filesystemName.toString(),
                                FileSystemTypeIsolated,
                                KURL(ParsedURLString, rootURL.toString()));
 }
 
 DOMFileSystem::DOMFileSystem(ExecutionContext* context,
                              const String& name,
                              FileSystemType type,
                              const KURL& rootURL)
     : DOMFileSystemBase(context, name, type, rootURL),
-      ContextClient(context),
+      ContextLifecycleObserver(context),
       m_numberOfPendingCallbacks(0),
       m_rootEntry(DirectoryEntry::create(this, DOMFilePath::root)) {}
 
 DirectoryEntry* DOMFileSystem::root() const {
   return m_rootEntry.get();
 }
 
 void DOMFileSystem::addPendingCallbacks() {
   ++m_numberOfPendingCallbacks;
 }
@@ skipping 78 matching lines @@
   }
 
   fileSystem()->createSnapshotFileAndReadMetadata(
       fileSystemURL,
       SnapshotFileCallback::create(this, fileEntry->name(), fileSystemURL,
                                    successCallback, errorCallback, m_context));
 }
 
 DEFINE_TRACE(DOMFileSystem) {
   DOMFileSystemBase::trace(visitor);
-  ContextClient::trace(visitor);
+  ContextLifecycleObserver::trace(visitor);
   visitor->trace(m_rootEntry);
 }
 
 }  // namespace blink