Privatize StrongBinding lifetime management

chrome/utility/image_decoder_impl.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_IMAGE_DECODER_IMPL_H_
 #define CHROME_UTILITY_IMAGE_DECODER_IMPL_H_
 
 #include "base/macros.h"
 #include "chrome/common/image_decoder.mojom.h"
-#include "mojo/public/cpp/bindings/strong_binding.h"
 
 class ImageDecoderImpl : public mojom::ImageDecoder {
  public:
+  ImageDecoderImpl();
   explicit ImageDecoderImpl(int64_t max_message_size);
-  explicit ImageDecoderImpl(
-      mojo::InterfaceRequest<mojom::ImageDecoder> request);
   ~ImageDecoderImpl() override;
 
   // Overridden from mojom::ImageDecoder:
   void DecodeImage(
       mojo::Array<uint8_t> encoded_data,
       mojom::ImageCodec codec,
       bool shrink_to_fit,
       const DecodeImageCallback& callback) override;
 
  private:
   int64_t max_message_size_;
-  mojo::StrongBinding<ImageDecoder> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageDecoderImpl);
 };
 
 #endif  // CHROME_UTILITY_IMAGE_DECODER_IMPL_H_