Connect BackgroundFetch to the OfflineItemCollection

content/public/browser/background_fetch_client.h

+// 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 CONTENT_PUBLIC_BROWSER_BACKGROUND_FETCH_CLIENT_H_
+#define CONTENT_PUBLIC_BROWSER_BACKGROUND_FETCH_CLIENT_H_
+
+#include <string>
+
+#include "content/common/content_export.h"
+
+namespace content {
+
+// The Background Fetch client enables the embedder to be given information
+// about the active Background Fetches, for example to provide a user interface,
+// and for the embedder to control the state of such fetches.
+class CONTENT_EXPORT BackgroundFetchClient {
+ public:
+  // Class for access to the BackgroundFetch system. Manages in progress fetches
+  // and supports pause, resume, cancel, and UI update.
+  class CONTENT_EXPORT Delegate {
+   public:
+    // Cancel all fetches associated with the |registration_id|.
+    virtual void CancelDownload(const std::string& registration_id) = 0;
+
+    // Pause all fetches associated with the |registration_id|.
+    virtual void PauseDownload(const std::string& registration_id) = 0;
+
+    // Resume any fetches associated with the |registration_id|.
+    virtual void ResumeDownload(const std::string& registration_id) = 0;
+
+   protected:
+    virtual ~Delegate() {}
+  };
+
+  // The client will maintain a weak reference to |delegate|. The provider must
+  // reset the delegate back to a `nullptr` when it's being destructed.
+  virtual void SetDelegate(Delegate* delegate) = 0;

[Peter Beverloo, 2017/03/31 11:54:06]

Could we add one //content -> //chrome (--> OIC) call to this interface now to
illustrate further usage? There are other mechanisms for single directional
embedder -> //content communication, so that may cause confusion.

[harkness, 2017/04/03 12:47:22]

I'll start working on them.

+
+ protected:
+  virtual ~BackgroundFetchClient() {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_BACKGROUND_FETCH_CLIENT_H_