Give the BackgroundFetchJobController a simple state.

content/browser/background_fetch/background_fetch_job_controller.h

Index: content/browser/background_fetch/background_fetch_job_controller.h
diff --git a/content/browser/background_fetch/background_fetch_job_controller.h b/content/browser/background_fetch/background_fetch_job_controller.h
index 5d4fdcc7f006abfde28b6c958df77fa485ed549b..eac97eff46b74f0a2de7a7463b1ba2169c1741b6 100644
--- a/content/browser/background_fetch/background_fetch_job_controller.h
+++ b/content/browser/background_fetch/background_fetch_job_controller.h
@@ -30,9 +30,10 @@ class StoragePartition;
 class CONTENT_EXPORT BackgroundFetchJobController
     : public DownloadItem::Observer {
  public:
+  enum class State { INITIALIZED, FETCHING, ABORTED, COMPLETED };
+
   using CompletedCallback =
-      base::OnceCallback<void(const BackgroundFetchRegistrationId&,
-                              bool /* aborted_by_developer */)>;
+      base::OnceCallback<void(BackgroundFetchJobController*)>;
 
   BackgroundFetchJobController(
       const BackgroundFetchRegistrationId& registration_id,
@@ -57,6 +58,9 @@ class CONTENT_EXPORT BackgroundFetchJobController
   // Called by the BackgroundFetchContext when the system is shutting down.
   void Shutdown();
 
+  // Returns the current state of this Job Controller.
+  State state() const { return state_; }
+
   // Returns the registration id for which this job is fetching data.
   const BackgroundFetchRegistrationId& registration_id() const {
     return registration_id_;
@@ -84,6 +88,9 @@ class CONTENT_EXPORT BackgroundFetchJobController
   // Options for the represented background fetch registration.
   BackgroundFetchOptions options_;
 
+  // The current state of this Job Controller.
+  State state_ = State::INITIALIZED;
+
   // TODO(peter): Deprecated, remove in favor of |registration_id|.
   std::string job_guid_;