[Offline pages] Add a builder and feature struct to policy

components/offline_pages/client_policy_controller.h

Index: components/offline_pages/client_policy_controller.h
diff --git a/components/offline_pages/client_policy_controller.h b/components/offline_pages/client_policy_controller.h
index 231d028d4a6e3bf0e79ce41e35efee983c47bce5..55da43d5965dda98ea0196399521d4ac3126ea70 100644
--- a/components/offline_pages/client_policy_controller.h
+++ b/components/offline_pages/client_policy_controller.h
@@ -33,6 +33,12 @@ class ClientPolicyController {
   // Get the client policy for |name_space|.
   const OfflinePageClientPolicy& GetPolicy(const std::string& name_space) const;
 
+  // Returns whether pages for |name_space| should be removed on cache reset.
+  bool IsRemovedOnCacheReset(const std::string& name_space) const;
+
+  // Returns whether pages for |name_space| are shown in Download UI.
+  bool IsSupportedByDownload(const std::string& name_space) const;
+
  private:
   // The map from name_space to a client policy. Will be generated
   // as pre-defined values for now.