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

components/offline_pages/core/background/offliner_stub.h

Index: components/offline_pages/core/background/offliner_stub.h
diff --git a/components/offline_pages/core/background/offliner_stub.h b/components/offline_pages/core/background/offliner_stub.h
index d6ddc2486bd70b8db6d7e1883aca550713305580..fa23c5686a6f736872ed7f831921b475e7eb2f27 100644
--- a/components/offline_pages/core/background/offliner_stub.h
+++ b/components/offline_pages/core/background/offliner_stub.h
@@ -9,6 +9,7 @@
 
 #include "base/callback_forward.h"
 #include "components/offline_pages/core/background/offliner.h"
+#include "components/offline_pages/core/background/resource_data_type.h"
 
 namespace offline_pages {
 
@@ -27,6 +28,10 @@ class OfflinerStub : public Offliner {
 
   bool HandleTimeout(int64_t request_id) override;
 
+  void ObserveResourceTracking(const ResourceDataType type,
+                               int64_t started_count,
+                               int64_t completed_count) override;
+
   void disable_loading() { disable_loading_ = true; }
 
   void enable_callback(bool enable) { enable_callback_ = enable; }