Reporting: Wrap existing classes in context.

net/reporting/reporting_delegate.h

Index: net/reporting/reporting_delegate.h
diff --git a/net/reporting/reporting_delegate.h b/net/reporting/reporting_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..57d01ab4a6ae138492f55986dc3947f3c34abe70
--- /dev/null
+++ b/net/reporting/reporting_delegate.h
@@ -0,0 +1,45 @@
+// 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 NET_REPORTING_REPORTING_DELEGATE_H_
+#define NET_REPORTING_REPORTING_DELEGATE_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "net/base/net_export.h"
+
+namespace base {
+class Value;
+}  // namespace base
+
+namespace net {
+
+// Delegate for things that the Reporting system can't do by itself, like
+// persisting data across embedder restarts.

[shivanisha, 2017/04/03 15:39:05]

How will this class interact with https://codereview.chromium.org/2751883003/
ReportingSerializer?

[Julia Tuttle, 2017/04/04 18:28:02]

The Serializer (which will eventually be renamed the Persister, and will gain
the ability to schedule its own work) will use GetPersistedData() to load data
from a past session once at startup, and PersistData() to save data to be
reloaded by a future session periodically.

[shivanisha, 2017/04/05 16:52:57]

A design level question:
- Currently it looks like the ReportingDelegate class is only associated with
the serialization aspects of reporting. Can we not just use the
ReportingSerializer for the same or is the ReportingDelegate being created for
any future enhancements?

[Julia Tuttle, 2017/04/06 17:08:16]

We can't use the ReportingSerializer for that; net can't directly modify prefs.
The ReportingDelegate is an interface that will be implemented in Chromium (or
other embedders) to allow reading/writing prefs.

[shivanisha, 2017/04/06 17:15:30]

Thanks.

+class NET_EXPORT ReportingDelegate {
+ public:
+  virtual ~ReportingDelegate();
+
+  // Gets previously persisted data, if any is available. Returns a null pointer
+  // if no data is available. Can be called any number of times.
+  virtual std::unique_ptr<const base::Value> GetPersistedData() = 0;
+
+  // Sets data to be persisted across embedder restarts. Ideally, this data will
+  // be returned by any future calls to GetPersistedData() in this or future
+  // sessions (until newer data is persisted), but no guarantee is made, since
+  // the underlying persistence mechanism may or may not be reliable.
+  virtual void PersistData(
+      std::unique_ptr<const base::Value> persisted_data) = 0;
+
+ protected:
+  ReportingDelegate();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ReportingDelegate);
+};
+
+}  // namespace net
+
+#endif  // NET_REPORTING_REPORTING_DELEGATE_H_