Implement Blob.close().

Source/core/fileapi/File.cpp

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 207 matching lines @@
     if (!getFileMetadata(m_path, metadata)) {
         snapshotSize = 0;
         snapshotModificationTime = invalidFileTime();
         return;
     }
 
     snapshotSize = metadata.length;
     snapshotModificationTime = metadata.modificationTime;
 }
 
+void File::close(ExecutionContext* executionContext)
+{
+    if (!hasBeenClosed()) {
+        m_hasBackingFile = false;
+        m_relativePath = String();
+        m_path = String();

[kinuko, 2014/02/12 12:52:00]

There're more fields in this class (e.g. m_name)-- should we also clear them?

[sof, 2014/02/12 12:53:46]

The name of the Blob isn't currently spec'ed as going away when closed.

[kinuko, 2014/02/12 13:26:25]

I see thanks. Could we clear m_fileSystemURL too then as it could be internally
used in a similar way as m_path?  (Also having a short comment about why we
don't clear m_name here might help avoiding similar questions)

[sof, 2014/02/12 22:28:26]

Yes, better do both.

[sof, 2014/02/13 09:59:57]

Done now.

+        invalidateSnapshotMetadata();
+        Blob::close(executionContext);
+    }
+}
+
 void File::appendTo(BlobData& blobData) const
 {
     if (!m_hasBackingFile) {
         Blob::appendTo(blobData);
         return;
     }
 
     // FIXME: This involves synchronous file operation. We need to figure out how to make it asynchronous.
     long long size;
     double modificationTime;
     captureSnapshot(size, modificationTime);
     if (!m_fileSystemURL.isEmpty()) {
         blobData.appendFileSystemURL(m_fileSystemURL, 0, size, modificationTime);
         return;
     }
     ASSERT(!m_path.isEmpty());
     blobData.appendFile(m_path, 0, size, modificationTime);
 }
 
 } // namespace WebCore