Pass Physical Web metadata through a struct

components/physical_web/data_source/fake_physical_web_data_source.h

Index: components/physical_web/data_source/fake_physical_web_data_source.h
diff --git a/components/physical_web/data_source/fake_physical_web_data_source.h b/components/physical_web/data_source/fake_physical_web_data_source.h
index 970e891b80cbc133a14146b3a0b012168de2f0e8..6ccd1de63d5a30d353e464a2dae9921b5caa88b9 100644
--- a/components/physical_web/data_source/fake_physical_web_data_source.h
+++ b/components/physical_web/data_source/fake_physical_web_data_source.h
@@ -43,6 +43,7 @@ class FakePhysicalWebDataSource : public PhysicalWebDataSource {
   void StopDiscovery() override;
 
   std::unique_ptr<base::ListValue> GetMetadata() override;
+  std::unique_ptr<MetadataList> GetMetadataList() override;
 
   bool HasUnresolvedDiscoveries() override;
 
@@ -51,12 +52,14 @@ class FakePhysicalWebDataSource : public PhysicalWebDataSource {
 
   // for testing
   void SetMetadata(std::unique_ptr<base::ListValue> metadata);
+  void SetMetadataList(std::unique_ptr<MetadataList> metadata_list);
   void NotifyOnFound(const GURL& url);
   void NotifyOnLost(const GURL& url);
   void NotifyOnDistanceChanged(const GURL& url, double distance_estimate);
 
  private:
   std::unique_ptr<base::ListValue> metadata_;
+  std::unique_ptr<MetadataList> metadata_list_;
   base::ObserverList<PhysicalWebListener> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(FakePhysicalWebDataSource);