Service Manager: Remove ServiceContext* arg from Service::OnStart()

mash/example/window_type_launcher/window_type_launcher.h

 // Copyright 2015 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 MASH_EXAMPLE_WINDOW_TYPE_LAUNCHER_WINDOW_TYPE_LAUNCHER_H_
 #define MASH_EXAMPLE_WINDOW_TYPE_LAUNCHER_WINDOW_TYPE_LAUNCHER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "mash/public/interfaces/launchable.mojom.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "services/service_manager/public/cpp/interface_factory.h"
 #include "services/service_manager/public/cpp/service.h"
 
-namespace service_manager {
-class ServiceContext;
-}
-
 namespace views {
 class AuraInit;
 class Widget;
 }
 
 class WindowTypeLauncher
     : public service_manager::Service,
       public mash::mojom::Launchable,
       public service_manager::InterfaceFactory<mash::mojom::Launchable> {
  public:
   WindowTypeLauncher();
   ~WindowTypeLauncher() override;
 
   void RemoveWindow(views::Widget* window);
 
  private:
   // service_manager::Service:
-  void OnStart(service_manager::ServiceContext* context) override;
+  void OnStart() override;
   bool OnConnect(const service_manager::ServiceInfo& remote_info,
                  service_manager::InterfaceRegistry* registry) override;
 
   // mash::mojom::Launchable:
   void Launch(uint32_t what, mash::mojom::LaunchMode how) override;
 
   // service_manager::InterfaceFactory<mash::mojom::Launchable>:
   void Create(const service_manager::Identity& remote_identity,
               mash::mojom::LaunchableRequest request) override;
 
-  service_manager::ServiceContext* context_ = nullptr;
-
   mojo::BindingSet<mash::mojom::Launchable> bindings_;
   std::vector<views::Widget*> windows_;
 
   std::unique_ptr<views::AuraInit> aura_init_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTypeLauncher);
 };
 
 #endif  // MASH_EXAMPLE_WINDOW_TYPE_LAUNCHER_WINDOW_TYPE_LAUNCHER_H_