Prefetching: Introduce store commands abstractions to be used by tasks.

chrome/browser/offline_pages/prefetch/prefetch_service_factory.cc

Index: chrome/browser/offline_pages/prefetch/prefetch_service_factory.cc
diff --git a/chrome/browser/offline_pages/prefetch/prefetch_service_factory.cc b/chrome/browser/offline_pages/prefetch/prefetch_service_factory.cc
index 92eed1c40328e06a1fafd57f5aaf200c70c3f40c..d93f77f4b9a8ad37de965f9cafa7e5701236e71a 100644
--- a/chrome/browser/offline_pages/prefetch/prefetch_service_factory.cc
+++ b/chrome/browser/offline_pages/prefetch/prefetch_service_factory.cc
@@ -14,8 +14,8 @@
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/offline_pages/core/prefetch/prefetch_dispatcher_impl.h"
 #include "components/offline_pages/core/prefetch/prefetch_gcm_app_handler.h"
-#include "components/offline_pages/core/prefetch/prefetch_in_memory_store.h"
 #include "components/offline_pages/core/prefetch/prefetch_service_impl.h"
+#include "components/offline_pages/core/prefetch/store/prefetch_store_command_factory.h"
 #include "components/offline_pages/core/prefetch/suggested_articles_observer.h"
 #include "content/public/browser/browser_context.h"
 
@@ -47,11 +47,12 @@ KeyedService* PrefetchServiceFactory::BuildServiceInstanceFor(
       base::MakeUnique<OfflineMetricsCollectorImpl>();
   auto suggested_articles_observer =
       base::MakeUnique<SuggestedArticlesObserver>(prefetch_dispatcher.get());
-  auto in_memory_store = base::MakeUnique<PrefetchInMemoryStore>();
+  // TODO: Instantiate an actual factory once one exists.

[dewittj, 2017/06/15 22:46:49]

nit: This makes prefetching crash if enabled.  Not an ideal state of affairs for
very long.

[carlosk, 2017/06/16 01:06:58]

Is it OK to leave it like that or would you prefer that I use the (just
extracted) test version instead? Note that that would require also including
those test files in the non-test build target.

+  std::unique_ptr<PrefetchStoreCommandFactory> store_command_factory;
 
   return new PrefetchServiceImpl(
       std::move(offline_metrics_collector), std::move(prefetch_dispatcher),
-      std::move(prefetch_gcm_app_handler), std::move(in_memory_store),
+      std::move(prefetch_gcm_app_handler), std::move(store_command_factory),
       std::move(suggested_articles_observer));
 }