Revert of [Service Manager] Get rid of dynamic service discovery

services/catalog/instance.h

Index: services/catalog/instance.h
diff --git a/services/catalog/instance.h b/services/catalog/instance.h
index fa1a4cb153f28167987c36c4c440db0c9150968b..7c67b893b386316ee532e1d9623322466004f2ca 100644
--- a/services/catalog/instance.h
+++ b/services/catalog/instance.h
@@ -18,19 +18,20 @@
 namespace catalog {
 
 class EntryCache;
-class ManifestProvider;
+class Reader;
 
 class Instance : public service_manager::mojom::Resolver,
                  public mojom::Catalog {
  public:
-  // Neither |system_cache| nor |service_manifest_provider| is owned.
-  // |service_manifest_provider| may be null
-  Instance(EntryCache* system_cache,
-           ManifestProvider* service_manifest_provider);
+  // |manifest_provider| may be null.
+  explicit Instance(Reader* system_reader);
   ~Instance() override;
 
   void BindResolver(service_manager::mojom::ResolverRequest request);
   void BindCatalog(mojom::CatalogRequest request);
+
+  // Called when |cache| has been populated by a directory scan.
+  void CacheReady(EntryCache* cache);
 
  private:
   // service_manager::mojom::Resolver:
@@ -53,14 +54,18 @@
   mojo::BindingSet<service_manager::mojom::Resolver> resolver_bindings_;
   mojo::BindingSet<mojom::Catalog> catalog_bindings_;
 
+  Reader* system_reader_;
+
   // A map of name -> Entry data structure for system-level packages (i.e. those
   // that are visible to all users).
   // TODO(beng): eventually add per-user applications.
-  EntryCache* const system_cache_;
+  EntryCache* system_cache_ = nullptr;
 
-  // A runtime interface the embedder can use to provide dynamic manifest data
-  // to be queried on-demand if something can't be found in |system_cache_|.
-  ManifestProvider* const service_manifest_provider_;
+  // We only bind requests for these interfaces once the catalog has been
+  // populated. These data structures queue requests until that happens.
+  std::vector<service_manager::mojom::ResolverRequest>
+      pending_resolver_requests_;
+  std::vector<mojom::CatalogRequest> pending_catalog_requests_;
 
   DISALLOW_COPY_AND_ASSIGN(Instance);
 };