Flesh out URLLoader's download_to_file function.

* tie the lifetime of the resulting temp file to the lifetime of the URLLoader
  (the plan is to later extend the lifetime of the temp file to support xhr.responseBlob)
* make it work in test_shell
* make it work for sync requests
* added OnDataDownloaded messages to report progress

A related BlobURL loading change.
* grab a reference to the blob early on to ensure it's still there when the 'job' is finally started.

TEST=manual and deletable_file_reference_unittest.cc
BUG=52486

Review URL: http://codereview.chromium.org/3165062

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@60378 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 49 insertions, 0 deletions

diff --git a/webkit/blob/deletable_file_reference.h b/webkit/blob/deletable_file_reference.h
new file mode 100644
index 0000000..9578c10
--- /dev/null
+++ b/webkit/blob/deletable_file_reference.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef WEBKIT_BLOB_DELETABLE_FILE_REFERENCE_H_
+#define WEBKIT_BLOB_DELETABLE_FILE_REFERENCE_H_
+#pragma once
+
+#include "base/file_path.h"
+#include "base/ref_counted.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace webkit_blob {
+
+// A refcounted wrapper around a FilePath that schedules the file
+// to be deleted upon final release.
+class DeletableFileReference : public base::RefCounted<DeletableFileReference> {
+ public:
+  // Returns a DeletableFileReference for the given path, if no reference
+  // for this path exists returns NULL.
+  static scoped_refptr<DeletableFileReference> Get(const FilePath& path);
+
+  // Returns a DeletableFileReference for the given path, creating a new
+  // reference if none yet exists.
+  static scoped_refptr<DeletableFileReference> GetOrCreate(
+      const FilePath& path, base::MessageLoopProxy* file_thread);
+
+  // The full file path.
+  const FilePath& path() const { return path_; }
+
+ private:
+  friend class base::RefCounted<DeletableFileReference>;
+
+  DeletableFileReference(
+      const FilePath& path, base::MessageLoopProxy* file_thread);
+  ~DeletableFileReference();
+
+  const FilePath path_;
+  scoped_refptr<base::MessageLoopProxy> file_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeletableFileReference);
+};
+
+}  // namespace webkit_blob
+
+#endif  // BASE_DELETABLE_FILE_REFERENCE_H_