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

components/image_fetcher/image_data_fetcher.cc

-// 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.
-
-#include "components/image_fetcher/image_data_fetcher.h"
-
-#include "net/base/load_flags.h"
-#include "net/url_request/url_fetcher.h"
-#include "net/url_request/url_fetcher_delegate.h"
-#include "net/url_request/url_request.h"
-#include "net/url_request/url_request_context_getter.h"
-#include "net/url_request/url_request_status.h"
-#include "url/gurl.h"
-
-namespace image_fetcher {
-
-// An active image URL fetcher request. The class contains any related request
-// state and logic for handling a single image url request.
-class ImageDataFetcher::ImageDataFetcherRequest
-    : public net::URLFetcherDelegate {
- public:
-  ImageDataFetcherRequest(const GURL& url,
-                          const ImageDataFetcherCallback& callback,
-                          ImageDataFetcher* image_url_fetcher);
-  ~ImageDataFetcherRequest() override {}
-
-  // Sends the URL requests.
-  void Start(net::URLRequestContextGetter* request_context);
-
- private:
-  // Method inherited from URLFetcherDelegate
-  void OnURLFetchComplete(const net::URLFetcher* source) override;
-
-  // The URL of the image to fetch.
-  const GURL url_;
-
-  // The callback to run after the image data was fetched. The callback will
-  // be run even if the image data could not be fetched successfully.
-  ImageDataFetcherCallback callback_;
-
-  // The ImageDataFetcher that owns the ImageDataFetcherRequest.
-  ImageDataFetcher* image_url_fetcher_;
-
-  std::unique_ptr<net::URLFetcher> url_fetcher_;
-
-  DISALLOW_COPY_AND_ASSIGN(ImageDataFetcherRequest);
-};
-
-ImageDataFetcher::ImageDataFetcherRequest::ImageDataFetcherRequest(
-    const GURL& url,
-    const ImageDataFetcherCallback& callback,
-    ImageDataFetcher* image_url_fetcher)
-    : url_(url),
-      callback_(callback),
-      image_url_fetcher_(image_url_fetcher) {
-}
-
-void ImageDataFetcher::ImageDataFetcherRequest::Start(
-    net::URLRequestContextGetter* request_context) {
-  DCHECK(!url_fetcher_);
-
-  url_fetcher_ = net::URLFetcher::Create(url_, net::URLFetcher::GET, this);
-  url_fetcher_->SetRequestContext(request_context);
-  url_fetcher_->Start();
-}
-
-void ImageDataFetcher::ImageDataFetcherRequest::OnURLFetchComplete(
-    const net::URLFetcher* source) {
-  // An empty string is passed to the callback in case on an unsuccessfull URL
-  // request.
-  std::string image_data;
-  if (source->GetStatus().status() == net::URLRequestStatus::SUCCESS) {
-    source->GetResponseAsString(&image_data);
-  }
-  callback_.Run(image_data);
-
-  // Remove the completed ImageDataFetcherRequest from the internal request
-  // queue. This must be last in the method.
-  image_url_fetcher_->RemoveImageDataFetcherRequest(url_);
-}
-
-ImageDataFetcher::ImageDataFetcher(
-    net::URLRequestContextGetter* url_request_context_getter)
-    : url_request_context_getter_(url_request_context_getter) {}
-
-ImageDataFetcher::~ImageDataFetcher() {}
-
-void ImageDataFetcher::FetchImageData(
-    const GURL& url, const ImageDataFetcherCallback& callback) {
-  std::unique_ptr<ImageDataFetcherRequest> request(
-      new ImageDataFetcherRequest(url, callback, this));
-  request->Start(url_request_context_getter_.get());
-  pending_requests_[url] = std::move(request);
-}
-
-void ImageDataFetcher::RemoveImageDataFetcherRequest(const GURL& image_url) {
-  size_t count = pending_requests_.erase(image_url);
-  DCHECK(count);
-}
-
-}  // namespace image_fetcher