Enable the mojo-based serial API in the renderer behind a flag.

extensions/browser/service_registration_manager.h

Index: extensions/browser/service_registration_manager.h
diff --git a/extensions/browser/service_registration_manager.h b/extensions/browser/service_registration_manager.h
index aab91e7aaf58c85da1d55cc0918eafc6352cf7f3..ad0d974b14051e040fdd738b701ab85ac6feb5ab 100644
--- a/extensions/browser/service_registration_manager.h
+++ b/extensions/browser/service_registration_manager.h
@@ -19,6 +19,9 @@ class RenderFrameHost;
 }
 
 namespace extensions {
+
+class ServiceRegistrationManagerTestApi;
+
 namespace internal {
 
 // A base class for forwarding calls to ServiceRegistry::AddService().
@@ -28,6 +31,8 @@ class ServiceFactoryBase {
 
   // Add this service factory to |service_registry|.
   virtual void Register(content::ServiceRegistry* service_registry) const = 0;
+
+  virtual std::string GetName() const = 0;
 };
 
 template <typename Interface>
@@ -43,6 +48,8 @@ class ServiceFactory : public ServiceFactoryBase {
     service_registry->AddService(factory_);
   }
 
+  virtual std::string GetName() const override { return Interface::Name_; }
+
  private:
   const base::Callback<void(mojo::InterfaceRequest<Interface>)> factory_;
   DISALLOW_COPY_AND_ASSIGN(ServiceFactory);
@@ -82,7 +89,18 @@ class ServiceRegistrationManager {
   // ServiceRegistry.
   void AddServicesToRenderFrame(content::RenderFrameHost* render_frame_host);
 
+ protected:
+  virtual void AddServiceToServiceRegistry(
+      content::ServiceRegistry* service_registry,
+      internal::ServiceFactoryBase* service_factory);
+
  private:
+  friend class ServiceRegistrationManagerTestApi;
+
+  static void SetServiceRegistrationManagerForTest(
+      ServiceRegistrationManager* service_registration_manager);
+  static void ClearServiceRegistrationManagerForTest();
+
   // All factories and their corresponding API permissions.
   std::vector<std::pair<std::string, linked_ptr<internal::ServiceFactoryBase>>>
       factories_;