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
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+// 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 {
+
+// Coordinates queueing and processing save page later requests.
+class RequestCoordinator {
+ public:
+  // Callback to report when the processing of a triggered task is complete.
+  typedef base::Callback<void()> ProcessingDoneCallback;
+
+  struct SavePageRequest {
+    // TODO(dougarnett): define and consider making stand-alone.
+  };
+
+  // TODO(dougarnett): How to inject Offliner factories and policy objects.
+  RequestCoordinator();
+
+  ~RequestCoordinator() {}
+
+  // Queues |request| to later load and save when system conditions allow.
+  bool SavePageLater(const SavePageRequest& request);
+
+  // Starts processing of one or more queued save page later requests.
+  // Returns whether processing was started and that caller should expect
+  // a callback. If processing was already active, returns false.
+  bool StartProcessing(const ProcessingDoneCallback& callback);
+
+  // Stops the current request processing if active. This is a way for
+  // caller to abort processing; otherwise, processing will complete on
+  // its own. In either case, the callback will be called when processing
+  // is stopped or complete.
+  void StopProcessing();
+
+  // TODO(dougarnett): add policy support methods.
+};
+
+}  // namespace offline_pages
+
+#endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_