Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/modules/filesystem/FileWriter.h

 /*
  * 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 39 matching lines @@
     : public EventTargetWithInlineData
     , public FileWriterBase
 #else
     : public FileWriterBase
     , public EventTargetWithInlineData
 #endif
     , public ActiveDOMObject
     , public WebFileWriterClient {
     REFCOUNTED_GARBAGE_COLLECTED_EVENT_TARGET(FileWriterBase);
     DEFINE_WRAPPERTYPEINFO();
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(FileWriter);
+    USING_GARBAGE_COLLECTED_MIXIN(FileWriter);
 public:
     static FileWriter* create(ExecutionContext*);
     ~FileWriter() override;
 
     enum ReadyState {
         INIT = 0,
         WRITING = 1,
         DONE = 2
     };
 
@@ skipping 56 matching lines @@
     long long m_numAborts;
     long long m_recursionDepth;
     double m_lastProgressNotificationTimeMS;
     Member<Blob> m_blobBeingWritten;
     int m_asyncOperationId;
 };
 
 } // namespace blink
 
 #endif // FileWriter_h