Create the BackgroundFetchBatchManager and initiate a download.

content/browser/background_fetch/background_fetch_context.h

Index: content/browser/background_fetch/background_fetch_context.h
diff --git a/content/browser/background_fetch/background_fetch_context.h b/content/browser/background_fetch/background_fetch_context.h
index 4fdbb4035112e473c82bbf9054874f87b703c226..926808a5144f78b46b9bbf5eb60c92e272dd16c7 100644
--- a/content/browser/background_fetch/background_fetch_context.h
+++ b/content/browser/background_fetch/background_fetch_context.h
@@ -8,12 +8,14 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "content/browser/background_fetch/background_fetch_data_manager.h"
+#include "content/browser/background_fetch/background_fetch_job_controller.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
+class BackgroundFetchJobInfo;
+class BackgroundFetchRequestInfo;
 class BrowserContext;
-class FetchRequest;
 class ServiceWorkerContextWrapper;
 
 // The BackgroundFetchContext is the central moderator of ongoing background
@@ -27,6 +29,7 @@ class CONTENT_EXPORT BackgroundFetchContext
   // that it can respond to service worker events such as unregister.
   BackgroundFetchContext(
       BrowserContext* browser_context,
+      StoragePartition* storage_partition,
       const scoped_refptr<ServiceWorkerContextWrapper>& context);
 
   // Init and Shutdown are for use on the UI thread when the StoragePartition is
@@ -41,12 +44,15 @@ class CONTENT_EXPORT BackgroundFetchContext
   }
 
  private:
-  void CreateRequest(const FetchRequest& fetch_request);
+  void CreateRequest(const BackgroundFetchJobInfo& job_info,

[Peter Beverloo, 2017/02/28 03:32:54]

Something to consider:

Blink will give us a sequence of ServiceWorkerFetchRequest objects. At some
point in the code we need to:

  - Consume the request body (included as a blob);
  - Store all information in that object, since we need to be able to
reconstruct them.

We need to think of a way to minimize the maintenance burden here. If
ServiceWorkerFetchRequest gets a new property, Background Fetch needs to be able
to fully serialize and deserialize it, and, as a second step, actually use it.

As such, have you considered that BackgroundFetchRequestInfo could actually have
a ServiceWorkerFetchRequest object as a member?

Anita's going to be able to write lots of automatable tests in this area, and
will need the information to hook up the events, so this is something we need to
at least consider.

[harkness, 2017/02/28 11:31:08]

That's an interesting idea, I'll definitely keep it in mind. I'm very much
looking forward to getting the MOJO service implementation connected to this.

+                     std::vector<BackgroundFetchRequestInfo>& request_infos);
 
   friend class base::RefCountedThreadSafe<BackgroundFetchContext>;
   ~BackgroundFetchContext();
 
+  BrowserContext* browser_context_;

[Peter Beverloo, 2017/02/28 03:32:54]

Unused, delete.

[harkness, 2017/02/28 11:31:08]

Done.

   scoped_refptr<ServiceWorkerContextWrapper> service_worker_context_;
+  BackgroundFetchJobController background_fetch_job_controller_;
   BackgroundFetchDataManager background_fetch_data_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundFetchContext);