API changes to support suspending requests

components/offline_pages/background/request_coordinator.h

 // 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_
 
 #include <memory>
 
 #include "base/callback.h"
@@ skipping 37 matching lines @@
    public:
     virtual ~Observer() = default;
 
     virtual void OnAdded(const SavePageRequest& request) = 0;
     virtual void OnCompleted(
         const SavePageRequest& request,
         RequestNotifier::BackgroundSavePageResult status) = 0;
     virtual void OnChanged(const SavePageRequest& request) = 0;
   };
 
+  enum class RequestAvailability {
+    AVAILABLE_TO_OFFLINER,
+    DISABLED_TO_OFFLINER,
+  };
+
   // Callback to report when a request was available.
   typedef base::Callback<void(const SavePageRequest& request)>
       RequestPickedCallback;
   // Callback to report when no request was available.
   typedef base::Callback<void(bool)> RequestNotPickedCallback;
 
   RequestCoordinator(std::unique_ptr<OfflinerPolicy> policy,
                      std::unique_ptr<OfflinerFactory> factory,
                      std::unique_ptr<RequestQueue> queue,
                      std::unique_ptr<Scheduler> scheduler,
                      net::NetworkQualityEstimator::NetworkQualityProvider*
                          network_quality_estimator);
 
   ~RequestCoordinator() override;
 
   // Queues |request| to later load and save when system conditions allow.
-  // Returns true if the page could be queued successfully.
-  bool SavePageLater(
-      const GURL& url, const ClientId& client_id, bool user_reqeusted);
+  // Returns an id if the page could be queued successfully, 0L otherwise.
+  int64_t SavePageLater(const GURL& url,
+                        const ClientId& client_id,
+                        bool user_reqeusted,

[Dmitry Titov, 2016/10/05 22:28:19]

typo: user_reqeusted -> user_requested

[Pete Williamson, 2016/10/05 22:57:46]

Nice catch!  Done.

+                        RequestAvailability availability);

[Dmitry Titov, 2016/10/05 22:28:19]

I'd rather have a "bool do_not_process" or "bool block_offlining".

It makes more sense to casual reader because the request is still created, and
even still causes the notification to pop up - but it is not being offlined yet.

[Pete Williamson, 2016/10/05 22:57:46]

I think that FGorski had the opposite feedback in the design doc, to prefer an
enum here.  I prefer an enum, so I'd like to go with that unless you feel
strongly about this one.

 
   // Callback specifying which request IDs were actually removed.
   typedef base::Callback<void(
       const RequestQueue::UpdateMultipleRequestResults&)>
       RemoveRequestsCallback;
 
   // Remove a list of requests by |request_id|.  This removes requests from the
   // request queue, and cancels an in-progress prerender.
   void RemoveRequests(const std::vector<int64_t>& request_ids,
                       const RemoveRequestsCallback& callback);
@@ skipping 17 matching lines @@
   // a callback. If processing was already active, returns false.
   bool StartProcessing(const DeviceConditions& device_conditions,
                        const base::Callback<void(bool)>& 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(Offliner::RequestStatus stop_status);
 
+  // Used to denote that the foreground thread is ready for the offliner
+  // to start work on a previously entered, but unavailable request.
+  void MakeAvailableToOffliner(int64_t request_id);
+
+  // If a request that is unavailable to the offliner is finished elsewhere,
+  // (by the tab helper synchronous download), send a notificaiton that it
+  // succeeded through our notificaiton system.
+  void MarkRequestCompleted(int64_t request_id);
+
   const Scheduler::TriggerConditions GetTriggerConditions(
       const bool user_requested);
 
   // A way for tests to set the callback in use when an operation is over.
   void SetProcessingCallbackForTest(const base::Callback<void(bool)> callback) {
     scheduler_callback_ = callback;
   }
 
   // Observers implementing the RequestCoordinator::Observer interface can
   // register here to get notifications of changes to request state.  This
@@ skipping 193 matching lines @@
   base::TimeDelta offliner_timeout_;
   // Allows us to pass a weak pointer to callbacks.
   base::WeakPtrFactory<RequestCoordinator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RequestCoordinator);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_