Replace deprecated calls to GetMetadata in Physical Web Zine provider

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 c10543e38eab802b0408a8c5cd81544b57553938..a84e762cfb685cc5cb2141b7120dd362dcc1e20c 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
@@ -14,13 +14,12 @@
 class GURL;
 
 namespace base {
-class DictionaryValue;
 class ListValue;
 }
 
 namespace physical_web {
 
-std::unique_ptr<base::DictionaryValue> CreatePhysicalWebPage(
+std::unique_ptr<Metadata> CreatePhysicalWebPage(
     const std::string& resolved_url,
     double distance_estimate,
     const std::string& group_id,
@@ -29,10 +28,10 @@ std::unique_ptr<base::DictionaryValue> CreatePhysicalWebPage(
     const std::string& description,
     const std::string& scanned_url);
 
-std::unique_ptr<base::DictionaryValue>
+std::unique_ptr<Metadata>
 CreateDummyPhysicalWebPage(int id, double distance, int timestamp);
 
-std::unique_ptr<base::ListValue> CreateDummyPhysicalWebPages(
+std::unique_ptr<MetadataList> CreateDummyPhysicalWebPages(
     const std::vector<int>& ids);
 
 class FakePhysicalWebDataSource : public PhysicalWebDataSource {