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

services/catalog/instance.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SERVICES_CATALOG_INSTANCE_H_
 #define SERVICES_CATALOG_INSTANCE_H_
 
 #include "base/files/file_path.h"
 #include "base/path_service.h"
 #include "base/values.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "services/catalog/entry.h"
 #include "services/catalog/public/interfaces/catalog.mojom.h"
 #include "services/catalog/store.h"
 #include "services/service_manager/public/cpp/interface_factory.h"
 #include "services/service_manager/public/interfaces/resolver.mojom.h"
 
 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:
   void ResolveServiceName(const std::string& service_name,
                           const ResolveServiceNameCallback& callback) override;
 
   // mojom::Catalog:
   void GetEntries(const base::Optional<std::vector<std::string>>& names,
                   const GetEntriesCallback& callback) override;
   void GetEntriesProvidingCapability(
       const std::string& capability,
       const GetEntriesProvidingCapabilityCallback& callback) override;
   void GetEntriesConsumingMIMEType(
       const std::string& mime_type,
       const GetEntriesConsumingMIMETypeCallback& callback) override;
   void GetEntriesSupportingScheme(
       const std::string& scheme,
       const GetEntriesSupportingSchemeCallback& callback) override;
 
   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);
 };
 
 }  // namespace catalog
 
 #endif  // SERVICES_CATALOG_INSTANCE_H_