Privatize StrongBinding lifetime management

chrome/utility/shell_handler_impl_win.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 CHROME_UTILITY_SHELL_HANDLER_IMPL_WIN_H_
 #define CHROME_UTILITY_SHELL_HANDLER_IMPL_WIN_H_
 
 #include "base/macros.h"
 #include "chrome/common/shell_handler_win.mojom.h"
-#include "mojo/public/cpp/bindings/strong_binding.h"
 
 // Implements the ShellHandler mojo interface.
 class ShellHandlerImpl : public mojom::ShellHandler {
  public:
+  ShellHandlerImpl();
+  ~ShellHandlerImpl() override;
+
   static void Create(mojom::ShellHandlerRequest request);
 
  private:
-  explicit ShellHandlerImpl(mojom::ShellHandlerRequest request);
-  ~ShellHandlerImpl() override;
-
   // mojom::ShellHandler:
   void IsPinnedToTaskbar(const IsPinnedToTaskbarCallback& callback) override;
 
-  mojo::StrongBinding<ShellHandler> binding_;
-
   DISALLOW_COPY_AND_ASSIGN(ShellHandlerImpl);
 };
 
 #endif  // CHROME_UTILITY_SHELL_HANDLER_IMPL_WIN_H_