Add service registration for apps APIs implemented as mojo services.

extensions/browser/service_registration_manager.h

+// Copyright 2014 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 EXTENSIONS_BROWSER_SERVICE_REGISTRATION_MANAGER_H_
+#define EXTENSIONS_BROWSER_SERVICE_REGISTRATION_MANAGER_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/linked_ptr.h"
+#include "content/public/common/service_registry.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+
+namespace content {
+class RenderFrameHost;
+}
+
+namespace extensions {
+namespace internal {
+
+class ServiceFactoryBase {

[raymes, 2014/10/15 20:22:50]

Maybe add a comment explaining what this is for and why you use this pattern.

[Sam McNally, 2014/10/20 00:22:07]

Done.

+ public:
+  virtual ~ServiceFactoryBase() {}
+
+  // Add this service factory to |service_registry|.
+  virtual void Register(content::ServiceRegistry* service_registry) const = 0;
+};
+
+template <typename Interface>
+class ServiceFactory : public ServiceFactoryBase {
+ public:
+  explicit ServiceFactory(
+      const base::Callback<void(mojo::InterfaceRequest<Interface>)>& factory)
+      : factory_(factory) {}
+  virtual ~ServiceFactory() {}
+
+  virtual void Register(
+      content::ServiceRegistry* service_registry) const override {
+    service_registry->AddService(factory_);
+  }
+
+ private:
+  const base::Callback<void(mojo::InterfaceRequest<Interface>)> factory_;
+  DISALLOW_COPY_AND_ASSIGN(ServiceFactory);
+};
+
+}  // namespace internal
+
+// A meta service registry. This allows registration of service factories and
+// their associated extensions API permission name. Whenever a RenderFrameHost
+// is created, each service that the render frame should have access to (based
+// on its SiteInstance), is added to the ServiceRegistry for that
+// RenderFrameHost.
+class ServiceRegistrationManager {
+ public:
+  ServiceRegistrationManager();
+  ~ServiceRegistrationManager();
+
+  static ServiceRegistrationManager* GetSharedInstance();
+
+  // Registers a ServiceFactory to be provided to extensions with the
+  // |permission_name| API permission.
+  //
+  // TODO(sammc): Add support for service factories that take the Extension*
+  // (or extension ID) and BrowserContext to allow fine-grained service and
+  // permission customization.
+  template <typename Interface>
+  void AddServiceFactory(
+      const std::string& permission_name,
+      const base::Callback<void(mojo::InterfaceRequest<Interface>)>& factory) {
+    factories_.push_back(
+        std::make_pair(permission_name,
+                       linked_ptr<internal::ServiceFactoryBase>(
+                           new internal::ServiceFactory<Interface>(factory))));
+  }
+
+  // Adds the service factories appropriate for |render_frame_host| to its
+  // ServiceRegistry.
+  void AddToRenderFrame(content::RenderFrameHost* render_frame_host);

[raymes, 2014/10/15 20:22:50]

nit: AddServicesToRenderFrame might be more descriptive here.

[Sam McNally, 2014/10/20 00:22:07]

Done.

+
+ private:
+  // All factories and their corresponding API permissions.
+  std::vector<std::pair<std::string, linked_ptr<internal::ServiceFactoryBase>>>
+      factories_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServiceRegistrationManager);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_SERVICE_REGISTRATION_MANAGER_H_