Add a way to send the resource percentage signal to the RC.

chrome/browser/offline_pages/background_loader_offliner.h

Index: chrome/browser/offline_pages/background_loader_offliner.h
diff --git a/chrome/browser/offline_pages/background_loader_offliner.h b/chrome/browser/offline_pages/background_loader_offliner.h
index cab1a501d94d03c14cc9f975a9882390134aff73..86e5233de50fc1e779ff530d00cd9a0b532a9946 100644
--- a/chrome/browser/offline_pages/background_loader_offliner.h
+++ b/chrome/browser/offline_pages/background_loader_offliner.h
@@ -46,6 +46,9 @@ class BackgroundLoaderOffliner : public Offliner,
                    const ProgressCallback& progress_callback) override;
   bool Cancel(const CancelCallback& callback) override;
   bool HandleTimeout(int64_t request_id) override;
+  void ObserveResourceTracking(const Offliner::ResourceDataType type,
+                               int64_t started_count,
+                               int64_t completed_count) override;
 
   // WebContentsObserver implementation.
   void DocumentAvailableInMainFrame() override;