Create skeleton for the Prefetching store and initial pipeline step.

components/offline_pages/core/prefetch/prefetch_service_impl.cc

Index: components/offline_pages/core/prefetch/prefetch_service_impl.cc
diff --git a/components/offline_pages/core/prefetch/prefetch_service_impl.cc b/components/offline_pages/core/prefetch/prefetch_service_impl.cc
index 4f557e5e6b4d4b76a96c6bcdbd9333a29f229a9f..0522133bf4f8352345d74c9062ca89edb302d26f 100644
--- a/components/offline_pages/core/prefetch/prefetch_service_impl.cc
+++ b/components/offline_pages/core/prefetch/prefetch_service_impl.cc
@@ -9,26 +9,26 @@
 #include "base/memory/ptr_util.h"
 #include "components/offline_pages/core/prefetch/offline_metrics_collector.h"
 #include "components/offline_pages/core/prefetch/prefetch_dispatcher_impl.h"
+#include "components/offline_pages/core/prefetch/prefetch_store.h"
 
 namespace offline_pages {
 
 PrefetchServiceImpl::PrefetchServiceImpl(
+    std::unique_ptr<PrefetchDispatcher> dispatcher,
+    std::unique_ptr<OfflineMetricsCollector> offline_metrics_collector,
     std::unique_ptr<PrefetchGCMHandler> gcm_handler,
-    std::unique_ptr<OfflineMetricsCollector> offline_metrics_collector)
-    : gcm_handler_(std::move(gcm_handler)),
-      dispatcher_(base::MakeUnique<PrefetchDispatcherImpl>()),
-      offline_metrics_collector_(std::move(offline_metrics_collector)) {}
+    std::unique_ptr<PrefetchStore> store)
+    : prefetch_dispatcher_(std::move(dispatcher)),
+      offline_metrics_collector_(std::move(offline_metrics_collector)),
+      gcm_handler_(std::move(gcm_handler)),
+      prefetch_store_(std::move(store)) {
+  prefetch_dispatcher_->SetService(this);
+}
 
 PrefetchServiceImpl::~PrefetchServiceImpl() = default;
 
-void PrefetchServiceImpl::ObserveContentSuggestionsService(
-    ntp_snippets::ContentSuggestionsService* service) {
-  suggested_articles_observer_ =
-      base::MakeUnique<SuggestedArticlesObserver>(service, this);
-}
-
-PrefetchDispatcher* PrefetchServiceImpl::GetDispatcher() {
-  return dispatcher_.get();
+PrefetchDispatcher* PrefetchServiceImpl::GetPrefetchDispatcher() {
+  return prefetch_dispatcher_.get();
 }
 
 OfflineMetricsCollector* PrefetchServiceImpl::GetOfflineMetricsCollector() {
@@ -39,6 +39,16 @@ PrefetchGCMHandler* PrefetchServiceImpl::GetPrefetchGCMHandler() {
   return gcm_handler_.get();
 }
 
+PrefetchStore* PrefetchServiceImpl::GetPrefetchStore() {
+  return prefetch_store_.get();
+}
+
+void PrefetchServiceImpl::ObserveContentSuggestionsService(
+    ntp_snippets::ContentSuggestionsService* service) {
+  suggested_articles_observer_ =
+      base::MakeUnique<SuggestedArticlesObserver>(service, this);
+}
+
 void PrefetchServiceImpl::Shutdown() {}
 
 }  // namespace offline_pages