********** Chromium Blob hacking

webkit/fileapi/local_file_system_operation.cc

Index: webkit/fileapi/local_file_system_operation.cc
===================================================================
--- webkit/fileapi/local_file_system_operation.cc	(revision 183651)
+++ webkit/fileapi/local_file_system_operation.cc	(working copy)
@@ -10,7 +10,9 @@
 #include "base/utf_string_conversions.h"
 #include "net/base/escape.h"
 #include "net/url_request/url_request_context.h"
+#include "webkit/blob/blob_storage_context.h"
 #include "webkit/blob/shareable_file_reference.h"
+#include "webkit/blob/blob_url_request_job_factory.h"
 #include "webkit/fileapi/async_file_util.h"
 #include "webkit/fileapi/cross_operation_delegate.h"
 #include "webkit/fileapi/file_observers.h"
@@ -248,10 +250,11 @@
 void LocalFileSystemOperation::Write(
     const net::URLRequestContext* url_request_context,
     const FileSystemURL& url,
-    const GURL& blob_url,
+    scoped_ptr<webkit_blob::BlobDataHandle> blob,
     int64 offset,
     const WriteCallback& callback) {
-  GetWriteClosure(url_request_context, url, blob_url, offset, callback).Run();
+  GetWriteClosure(url_request_context, url, blob.Pass(), offset, callback)
+      .Run();
 }
 
 void LocalFileSystemOperation::Truncate(const FileSystemURL& url, int64 length,
@@ -584,7 +587,7 @@
 base::Closure LocalFileSystemOperation::GetWriteClosure(
     const net::URLRequestContext* url_request_context,
     const FileSystemURL& url,
-    const GURL& blob_url,
+    scoped_ptr<webkit_blob::BlobDataHandle> blob_handle,
     int64 offset,
     const WriteCallback& callback) {
   DCHECK(SetPendingOperationType(kOperationWrite));
@@ -608,15 +611,19 @@
                       base::PLATFORM_FILE_ERROR_SECURITY);
   }
 
-  DCHECK(blob_url.is_valid());
   file_writer_delegate_.reset(new FileWriterDelegate(
       base::Bind(&LocalFileSystemOperation::DidWrite,
                  weak_factory_.GetWeakPtr(), url),
       writer.Pass()));
 
   write_callback_ = callback;
+
+  // Use a URLRequest to read the blob data that's to be written to the file.
   scoped_ptr<net::URLRequest> blob_request(url_request_context->CreateRequest(
-      blob_url, file_writer_delegate_.get()));
+      GURL("blob://see_user_data/"), file_writer_delegate_.get()));
+  webkit_blob::BlobProtocolHandler::SetRequestedBlobDataHandle(
+      blob_request.get(),
+      blob_handle.Pass());
 
   return base::Bind(&FileWriterDelegate::Start,
                     base::Unretained(file_writer_delegate_.get()),