Download driver for components/download.

components/download/content/download_driver_impl.h

Index: components/download/content/download_driver_impl.h
diff --git a/components/download/content/download_driver_impl.h b/components/download/content/download_driver_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..8d3a6b312615f52970f0c704c5e292b4d3ae2a71
--- /dev/null
+++ b/components/download/content/download_driver_impl.h
@@ -0,0 +1,56 @@
+// Copyright 2017 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 COMPONENTS_DOWNLOAD_CONTENT_DOWNLOAD_DRIVER_IMPL_H_
+#define COMPONENTS_DOWNLOAD_CONTENT_DOWNLOAD_DRIVER_IMPL_H_
+
+#include <string>
+
+#include "components/download/internal/download_driver.h"
+#include "components/download/public/download_params.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/download_manager.h"
+
+namespace download {
+
+// Aggregates and handles all interaction between download service and content
+// download logic.
+class DownloadDriverImpl : public DownloadDriver,
+                           public content::DownloadManager::Observer,
+                           public content::DownloadItem::Observer {
+ public:
+  DownloadDriverImpl(content::DownloadManager* manager);
+  ~DownloadDriverImpl() override;
+
+  // DownloadDriver implementation.
+  void Start(const DownloadParams& params) override;
+  void Cancel(const std::string& guid) override;
+  void Pause(const std::string& guid) override;
+  void Resume(const std::string& guid) override;
+  bool IsReady() const override;
+  void SetObserver(DownloadDriver::Observer* observer) override;

[David Trainor- moved to gerrit, 2017/05/15 20:08:14]

Should we just have an initialize method that takes a Client?

[xingliu, 2017/05/17 19:34:52]

Done.

+
+ private:
+  // content::DownloadItem::Observer implementation.
+  void OnDownloadUpdated(content::DownloadItem* item) override;
+
+  // content::DownloadManager::Observer implementation.
+  void OnDownloadCreated(content::DownloadManager* manager,
+                         content::DownloadItem* item) override;
+  void OnManagerInitialized() override;
+  void ManagerGoingDown(content::DownloadManager* manager) override;
+
+  // Low level download handle.
+  content::DownloadManager* download_manager_;
+
+  // The observer that receives updates from low level download logic.
+  // Can be nullptr when no updates are needed by the download service.
+  DownloadDriver::Observer* observer_;

[David Trainor- moved to gerrit, 2017/05/15 20:08:14]

Can this be called Client or something non-observer? Observer just seems like a
1:many concept.

[xingliu, 2017/05/17 19:34:52]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(DownloadDriverImpl);
+};
+
+}  // namespace download
+
+#endif  // COMPONENTS_DOWNLOAD_CONTENT_DOWNLOAD_DRIVER_IMPL_H_