********** WebCore blob hacking

WebCore/Modules/filesystem/DOMFileSystemSync.cpp

Index: WebCore/Modules/filesystem/DOMFileSystemSync.cpp
===================================================================
--- WebCore/Modules/filesystem/DOMFileSystemSync.cpp	(revision 140218)
+++ WebCore/Modules/filesystem/DOMFileSystemSync.cpp	(working copy)
@@ -113,10 +113,11 @@
     {
     }
 
-    void didReadMetadata(const FileMetadata& metadata)
+    virtual void didCreateSnapshotFile(const FileMetadata& metadata, PassRefPtr<BlobDataHandle> snapshot)
     {
         // For regular filesystem types (temporary or persistent), we should not cache file metadata as it could change File semantics.
-        // For other filesystem types (which could be platform-specific ones), there's a chance that the files are on remote filesystem. If the port has returned metadata just pass it to File constructor (so we may cache the metadata).
+        // For other filesystem types (which could be platform-specific ones), there's a chance that the files are on remote filesystem.
+        // If the port has returned metadata just pass it to File constructor (so we may cache the metadata).
         // FIXME: We should use the snapshot metadata for all files.
         // https://www.w3.org/Bugs/Public/show_bug.cgi?id=17746
         if (m_type == FileSystemTypeTemporary || m_type == FileSystemTypePersistent) {
@@ -128,6 +129,12 @@
             // Otherwise create a File from the FileSystem URL.
             m_result->m_file = File::createForFileSystemFile(m_url, metadata).get();
         }
+
+        // We can't directly use the snapshot blob data handle because the content type on it hasn't been set.
+        // Having a chain of custody thru thread bridging of that instance up until now, *after* we've coined a File with a new handle
+        // that has the correct type set on it, allows the blob storage system to track when a temp file can and can't
+        // be safely deleted.
+        // FIXME: Maybe add a BlobDataHandle/BlobRegistry methods to clone a blob with a new type?
     }
 private:
     CreateFileHelper(PassRefPtr<CreateFileResult> result, const String& name, const KURL& url, FileSystemType type)