Fix and refactor downloaded file handling in the loading stack

content/browser/loader/downloaded_temp_file_impl.h

Index: content/browser/loader/downloaded_temp_file_impl.h
diff --git a/content/browser/loader/downloaded_temp_file_impl.h b/content/browser/loader/downloaded_temp_file_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..e4a44d55b0f56f9247e41b242df14947eaaeed66
--- /dev/null
+++ b/content/browser/loader/downloaded_temp_file_impl.h
@@ -0,0 +1,59 @@
+// Copyright 2016 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 CONTENT_BROWSER_LOADER_DOWNLOADED_TEMP_FILE_IMPL_H_
+#define CONTENT_BROWSER_LOADER_DOWNLOADED_TEMP_FILE_IMPL_H_
+
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "content/common/content_export.h"
+#include "content/common/url_loader_factory.mojom.h"
+#include "mojo/public/cpp/bindings/binding.h"
+
+namespace storage {
+class ShareableFileReference;
+}
+
+namespace content {
+
+class ResourceDispatcherHostImpl;
+
+// DownloadedTempFileImpl is created on the download_to_file mode of resource
+// loading. The instance is held by ResourceDispatcherHostImpl and slightly
+// outlives URLLoader until the client destroyes the interface.
+class CONTENT_EXPORT DownloadedTempFileImpl final
+    : public mojom::DownloadedTempFile {
+ public:
+  DownloadedTempFileImpl(ResourceDispatcherHostImpl* rdh,
+                         int child_id,
+                         int request_id,
+                         const base::FilePath& path);
+  ~DownloadedTempFileImpl() override;
+
+  mojo::InterfacePtr<mojom::DownloadedTempFile> CreateInterfacePtrAndBind();
+
+  int child_id() const { return child_id_; }
+  int request_id() const { return request_id_; }
+  const scoped_refptr<storage::ShareableFileReference>& reference() const {
+    return reference_;
+  }
+
+ private:
+  void OnConnectionError();
+
+  mojo::Binding<DownloadedTempFile> binding_;
+
+  ResourceDispatcherHostImpl* rdh_;
+  int child_id_;
+  int request_id_;
+
+  scoped_refptr<storage::ShareableFileReference> reference_;
+
+  DISALLOW_COPY_AND_ASSIGN(DownloadedTempFileImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_DOWNLOADED_TEMP_FILE_IMPL_H_