Oilpan: move core/fileapi to oilpan's heap.

Source/modules/filesystem/FileWriter.h

Index: Source/modules/filesystem/FileWriter.h
diff --git a/Source/modules/filesystem/FileWriter.h b/Source/modules/filesystem/FileWriter.h
index 7306f8b78470a456f888cb22e9495e9476b44b76..cea0b69299135052d608e35b0ff38b44c74ee511 100644
--- a/Source/modules/filesystem/FileWriter.h
+++ b/Source/modules/filesystem/FileWriter.h
@@ -36,6 +36,7 @@
 #include "core/dom/ExecutionContext.h"
 #include "core/events/EventTarget.h"
 #include "core/fileapi/FileError.h"
+#include "heap/Handle.h"
 #include "modules/filesystem/FileWriterBase.h"
 #include "public/platform/WebFileWriterClient.h"
 #include "wtf/PassRefPtr.h"
@@ -106,7 +107,7 @@ private:
 
     void setError(FileError::ErrorCode, ExceptionState&);
 
-    RefPtr<FileError> m_error;
+    RefPtrWillBePersistent<FileError> m_error;
     ReadyState m_readyState;
     Operation m_operationInProgress;
     Operation m_queuedOperation;
@@ -116,7 +117,7 @@ private:
     long long m_numAborts;
     long long m_recursionDepth;
     double m_lastProgressNotificationTimeMS;
-    RefPtr<Blob> m_blobBeingWritten;
+    RefPtrWillBePersistent<Blob> m_blobBeingWritten;
 };
 
 } // namespace WebCore