Revert of Split the code for fetching images and for decoding images into two separate classes.

chrome/browser/search/suggestions/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_BROWSER_SEARCH_SUGGESTIONS_IMAGE_DECODER_IMPL_H_
-#define CHROME_BROWSER_SEARCH_SUGGESTIONS_IMAGE_DECODER_IMPL_H_
-
-#include <memory>
-#include <vector>
-
-#include "chrome/browser/image_decoder.h"
-#include "components/image_fetcher/image_decoder.h"
-
-class SkBitmap;
-
-namespace suggestions {
-
-// image_fetcher::ImageDecoder Implementation.
-class ImageDecoderImpl : public image_fetcher::ImageDecoder {
- public:
-  ImageDecoderImpl();
-  ~ImageDecoderImpl() override;
-
-  void DecodeImage(
-      const std::string& image_data,
-      const image_fetcher::ImageDecodedCallback& callback) override;
-
- private:
-  class DecodeImageRequest;
-
-  // Removes the passed image decode |request| from the internal request queue.
-  void RemoveDecodeImageRequest(DecodeImageRequest* request);
-
-  // All active image decoding requests.
-  std::vector<std::unique_ptr<DecodeImageRequest>> decode_image_requests_;
-
-  DISALLOW_COPY_AND_ASSIGN(ImageDecoderImpl);
-};
-
-}  // namespace suggestions
-
-#endif  // CHROME_BROWSER_SEARCH_SUGGESTIONS_IMAGE_DECODER_IMPL_H_
-