Defines initial inner circle of interfaces for background offlining.

components/offline_pages/background/request_coordinator.h

Index: components/offline_pages/background/request_coordinator.h
diff --git a/components/offline_pages/background/request_coordinator.h b/components/offline_pages/background/request_coordinator.h
new file mode 100644
index 0000000000000000000000000000000000000000..da1ff1677cfca71ea3ebfbd2d9fae07d1d8870f0
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+++ b/components/offline_pages/background/request_coordinator.h
@@ -0,0 +1,40 @@
+// 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 COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_
+#define COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_
+
+namespace offline_pages {
+
+class SavePageRequest;
+
+// Coordinates queueing and processing save page later requests.
+class RequestCoordinator : public KeyedService {

[Pete Williamson, 2016/04/26 00:52:19]

KeyedService -> BrowserContextKeyedService

Once we have a KeyedService, we will also need a factory (maybe better to not
inherit from KeyedService yet, and add that with a future change including the
factory)

[Pete Williamson, 2016/04/26 00:56:13]

Oops, my bad, it looks like it is KeyedService after all.  (The Factory is
BrowserContextKeyedServiceFactory).

[dougarnett, 2016/04/26 15:50:38]

I'm happy to take out KeyedService for this CL or leave in if sufficient as is
and seems helpful.

[Pete Williamson, 2016/04/26 16:40:59]

Let's take out the KeyedService, and add it back when we add a factory.

+ public:
+  // Callback to report when the processing of a triggered task is complete.
+  typedef base::Callback<void()> ProcessingDoneCallback;
+
+  // TODO(dougarnett): How to inject Offliner factories and policy objects.
+  RequestCoordinator();
+
+  virtual ~RequestCoordinator() {}
+
+  // Handles shutdown of KeyedService.
+  virtual void Shutdown() = 0;

[Pete Williamson, 2016/04/26 00:52:19]

Why make these pure virtual?  We don't really need an abstract base class for an
interface, I think a regular .h file would work as well (we could always
separate out an implementation class later if we want one, but until then, we
could have the implementation in the RequestCoordinator class).

[dougarnett, 2016/04/26 15:50:38]

Done.

+
+  // Queues |request| to later load and save when system conditions allow.
+  virtual bool SavePageLater(const SavePageRequest& request) = 0;
+
+  // Starts processing of one or more queued save page later requests.
+  virtual void StartProcessing(const ProcessingDoneCallback& callback) = 0;
+
+  // Stops the current request processing if active.
+  virtual void StopProcessing() = 0;
+
+  // TODO(dougarnett): add policy support methods.
+};
+
+}  // namespace offline_pages
+
+#endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_