Pass the ImageDecoder to the ImageFetcher at creation time.

chrome/browser/search/suggestions/image_fetcher_impl.h

-// Copyright 2014 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_FETCHER_IMPL_H_
-#define CHROME_BROWSER_SEARCH_SUGGESTIONS_IMAGE_FETCHER_IMPL_H_
-
-#include <map>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "base/callback.h"
-#include "base/macros.h"
-#include "components/image_fetcher/image_data_fetcher.h"
-#include "components/image_fetcher/image_decoder.h"
-#include "components/image_fetcher/image_fetcher.h"
-#include "url/gurl.h"
-
-namespace gfx {
-class Image;
-}
-
-namespace net {
-class URLRequestContextGetter;
-}
-
-// TODO(markusheintz): Move the ImageFetcherImpl to components/image_fetcher
-namespace suggestions {
-
-// image_fetcher::ImageFetcher implementation.
-class ImageFetcherImpl : public image_fetcher::ImageFetcher {
- public:
-  explicit ImageFetcherImpl(net::URLRequestContextGetter* url_request_context);
-  ~ImageFetcherImpl() override;
-
-  void SetImageFetcherDelegate(
-      image_fetcher::ImageFetcherDelegate* delegate) override;
-
-  void StartOrQueueNetworkRequest(
-      const std::string& id,
-      const GURL& image_url,
-      base::Callback<void(const std::string&, const gfx::Image&)> callback)
-      override;
-
- private:
-  using CallbackVector =
-      std::vector<base::Callback<void(const std::string&, const gfx::Image&)>>;
-
-  // State related to an image fetch (id, pending callbacks).
-  struct ImageRequest {
-    ImageRequest();
-    ImageRequest(const ImageRequest& other);
-    ~ImageRequest();
-
-    void swap(ImageRequest* other) {
-      std::swap(id, other->id);
-      std::swap(callbacks, other->callbacks);
-    }
-
-    std::string id;
-    // Queue for pending callbacks, which may accumulate while the request is in
-    // flight.
-    CallbackVector callbacks;
-  };
-
-  using ImageRequestMap = std::map<const GURL, ImageRequest>;
-
-  // Processes image URL fetched events. This is the continuation method used
-  // for creating callbacks that are passed to the ImageDataFetcher.
-  void OnImageURLFetched(const GURL& image_url, const std::string& image_data);
-
-  // Processes image decoded events. This is the continuation method used for
-  // creating callbacks that are passed to the ImageDecoder.
-  void OnImageDecoded(const GURL& image_url, const gfx::Image& image);
-
-
-  image_fetcher::ImageFetcherDelegate* delegate_;
-
-  net::URLRequestContextGetter* url_request_context_;
-
-  std::unique_ptr<image_fetcher::ImageDecoder> image_decoder_;
-
-  std::unique_ptr<image_fetcher::ImageDataFetcher> image_data_fetcher_;
-
-  // Map from each image URL to the request information (associated website
-  // url, fetcher, pending callbacks).
-  ImageRequestMap pending_net_requests_;
-
-  DISALLOW_COPY_AND_ASSIGN(ImageFetcherImpl);
-};
-
-}  // namespace suggestions
-
-#endif  // CHROME_BROWSER_SEARCH_SUGGESTIONS_IMAGE_FETCHER_IMPL_H_