[Background Fetch] Tidy up getting/activating pending requests

content/browser/background_fetch/background_fetch_data_manager.h

Index: content/browser/background_fetch/background_fetch_data_manager.h
diff --git a/content/browser/background_fetch/background_fetch_data_manager.h b/content/browser/background_fetch/background_fetch_data_manager.h
index ab17f484b294035ae86e61cab08e76cd929cb171..0de548e1ed7b219345f26fbfeb804f7381dc595c 100644
--- a/content/browser/background_fetch/background_fetch_data_manager.h
+++ b/content/browser/background_fetch/background_fetch_data_manager.h
@@ -33,9 +33,8 @@ class ChromeBlobStorageContext;
 // which will keep the metadata up to date.
 class CONTENT_EXPORT BackgroundFetchDataManager {
  public:
-  using CreateRegistrationCallback = base::OnceCallback<void(
-      blink::mojom::BackgroundFetchError,
-      std::vector<scoped_refptr<BackgroundFetchRequestInfo>>)>;
+  using CreateRegistrationCallback =
+      base::OnceCallback<void(blink::mojom::BackgroundFetchError)>;
   using DeleteRegistrationCallback =
       base::OnceCallback<void(blink::mojom::BackgroundFetchError)>;
   using NextRequestCallback =
@@ -58,6 +57,11 @@ class CONTENT_EXPORT BackgroundFetchDataManager {
       const BackgroundFetchOptions& options,
       CreateRegistrationCallback callback);
 
+  // Activates the next pending request, if any, such that it is ready to be
+  // started, and invokes the |callback| with that request, else a null request.
+  void ActivateNextRequest(const BackgroundFetchRegistrationId& registration_id,
+                           NextRequestCallback callback);

[Peter Beverloo, 2017/07/11 16:10:55]

I'm not a fan of "Activate". The JobController "starts" the request, the
DataManager "gets" it from storage -- it doesn't actually activate anything.
WDYT?

[johnme, 2017/07/12 13:13:09]

I've renamed this to PopNextRequest, since the key point is that it's no longer
in the pending queue.

+
   // Marks that the |request|, part of the Background Fetch identified by
   // |registration_id|, has been started as |download_guid|.
   void MarkRequestAsStarted(
@@ -68,7 +72,7 @@ class CONTENT_EXPORT BackgroundFetchDataManager {
   // Marks that the |request|, part of the Background Fetch identified by
   // |registration_id|, has completed. Will invoke the |callback| with the
   // next request, if any, when the operation has completed.
-  void MarkRequestAsCompleteAndGetNextRequest(
+  void MarkRequestAsCompleteAndActivateNextRequest(
       const BackgroundFetchRegistrationId& registration_id,
       BackgroundFetchRequestInfo* request,
       NextRequestCallback callback);