[Offline Prefetch] Backoff support for PrefetchBackgroundTask

components/offline_pages/core/prefetch/prefetch_dispatcher.h

Index: components/offline_pages/core/prefetch/prefetch_dispatcher.h
diff --git a/components/offline_pages/core/prefetch/prefetch_dispatcher.h b/components/offline_pages/core/prefetch/prefetch_dispatcher.h
index 36f9b206de3b4931cd2951798012fbeac27d9977..5c147ed567aa10cf23f42db4e2bd17f5796ca578 100644
--- a/components/offline_pages/core/prefetch/prefetch_dispatcher.h
+++ b/components/offline_pages/core/prefetch/prefetch_dispatcher.h
@@ -39,9 +39,9 @@ class PrefetchDispatcher {
     ScopedBackgroundTask() = default;
     virtual ~ScopedBackgroundTask() = default;
 
-    // Used on destruction to inform the system about whether rescheduling is
-    // required.
-    virtual void SetNeedsReschedule(bool reschedule) = 0;
+    // Used on destruction to inform the system about whether rescheduling with
+    // or without backoff is required.
+    virtual void SetNeedsReschedule(bool reschedule, bool backoff) = 0;
   };
 
   virtual ~PrefetchDispatcher() = default;
@@ -70,7 +70,7 @@ class PrefetchDispatcher {
   // Called when a task must stop immediately due to system constraints. After
   // this call completes, the system will reschedule the task based on whether
   // SetNeedsReschedule has been called.
-  virtual void StopBackgroundTask(ScopedBackgroundTask* task) = 0;
+  virtual void StopBackgroundTask(bool signaled_by_system) = 0;

[dewittj, 2017/05/31 21:33:33]

Instead of signaled_by_system, can you please have a
RequestFinishBackgroundTaskForTest() that can be used in testing? Otherwise the
parameter implies functionality that just doesn't exist in the production
system.

[jianli, 2017/06/01 00:09:59]

Done.

 };
 
 }  // namespace offline_pages