Move ImageFetcher to its own target.

ios/chrome/browser/net/image_fetcher.mm

-// Copyright 2012 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.
-
-#import "ios/chrome/browser/net/image_fetcher.h"
-
-#import <Foundation/Foundation.h>
-#include <stddef.h>
-
-#include "base/bind.h"
-#include "base/location.h"
-#include "base/mac/scoped_nsobject.h"
-#include "base/task_runner.h"
-#include "ios/chrome/browser/webp_transcode/webp_decoder.h"
-#include "ios/web/public/web_thread.h"
-#include "net/base/load_flags.h"
-#include "net/http/http_response_headers.h"
-#include "net/url_request/url_fetcher.h"
-#include "net/url_request/url_request_context_getter.h"
-
-namespace {
-
-class WebpDecoderDelegate : public webp_transcode::WebpDecoder::Delegate {
- public:
-  NSData* data() const { return decoded_image_; }
-
-  // WebpDecoder::Delegate methods
-  void OnFinishedDecoding(bool success) override {
-    if (!success)
-      decoded_image_.reset();
-  }
-  void SetImageFeatures(
-      size_t total_size,
-      webp_transcode::WebpDecoder::DecodedImageFormat format) override {
-    decoded_image_.reset([[NSMutableData alloc] initWithCapacity:total_size]);
-  }
-  void OnDataDecoded(NSData* data) override {
-    DCHECK(decoded_image_);
-    [decoded_image_ appendData:data];
-  }
- private:
-  ~WebpDecoderDelegate() override {}
-  base::scoped_nsobject<NSMutableData> decoded_image_;
-};
-
-// Content-type header for WebP images.
-static const char kWEBPMimeType[] = "image/webp";
-
-// Returns a NSData object containing the decoded image.
-// Returns nil in case of failure.
-base::scoped_nsobject<NSData> DecodeWebpImage(
-    const base::scoped_nsobject<NSData>& webp_image) {
-  scoped_refptr<WebpDecoderDelegate> delegate(new WebpDecoderDelegate);
-  scoped_refptr<webp_transcode::WebpDecoder> decoder(
-      new webp_transcode::WebpDecoder(delegate.get()));
-  decoder->OnDataReceived(webp_image);
-  DLOG_IF(ERROR, !delegate->data()) << "WebP image decoding failed.";
-  return base::scoped_nsobject<NSData>([delegate->data() retain]);
-}
-
-}  // namespace
-
-ImageFetcher::ImageFetcher(const scoped_refptr<base::TaskRunner>& task_runner)
-    : request_context_getter_(nullptr),
-      task_runner_(task_runner),
-      weak_factory_(this) {
-  DCHECK(task_runner_.get());
-}
-
-ImageFetcher::~ImageFetcher() {
-  // Delete all the entries in the |downloads_in_progress_| map.  This will in
-  // turn cancel all of the requests.
-  for (const auto& pair : downloads_in_progress_) {
-    [pair.second release];
-    delete pair.first;
-  }
-}
-
-void ImageFetcher::StartDownload(
-    const GURL& url,
-    ImageFetchedCallback callback,
-    const std::string& referrer,
-    net::URLRequest::ReferrerPolicy referrer_policy) {
-  DCHECK(request_context_getter_.get());
-  net::URLFetcher* fetcher =
-      net::URLFetcher::Create(url, net::URLFetcher::GET, this).release();
-  downloads_in_progress_[fetcher] = [callback copy];
-  fetcher->SetLoadFlags(
-      net::LOAD_DO_NOT_SEND_COOKIES | net::LOAD_DO_NOT_SAVE_COOKIES |
-      net::LOAD_DO_NOT_SEND_AUTH_DATA);
-  fetcher->SetRequestContext(request_context_getter_.get());
-  fetcher->SetReferrer(referrer);
-  fetcher->SetReferrerPolicy(referrer_policy);
-  fetcher->Start();
-}
-
-void ImageFetcher::StartDownload(
-    const GURL& url, ImageFetchedCallback callback) {
-  ImageFetcher::StartDownload(
-      url, callback, std::string(), net::URLRequest::NEVER_CLEAR_REFERRER);
-}
-
-// Delegate callback that is called when URLFetcher completes.  If the image
-// was fetched successfully, creates a new NSData and returns it to the
-// callback, otherwise returns nil to the callback.
-void ImageFetcher::OnURLFetchComplete(const net::URLFetcher* fetcher) {
-  if (downloads_in_progress_.find(fetcher) == downloads_in_progress_.end()) {
-    LOG(ERROR) << "Received callback for unknown URLFetcher " << fetcher;
-    return;
-  }
-
-  // Ensures that |fetcher| will be deleted in the event of early return.
-  std::unique_ptr<const net::URLFetcher> fetcher_deleter(fetcher);
-
-  // Retrieves the callback and ensures that it will be deleted in the event
-  // of early return.
-  base::mac::ScopedBlock<ImageFetchedCallback> callback(
-      downloads_in_progress_[fetcher]);
-
-  // Remove |fetcher| from the map.
-  downloads_in_progress_.erase(fetcher);
-
-  // Make sure the request was successful. For "data" requests, the response
-  // code has no meaning, because there is no actual server (data is encoded
-  // directly in the URL). In that case, set the response code to 200 (OK).
-  const GURL& original_url = fetcher->GetOriginalURL();
-  const int http_response_code = original_url.SchemeIs("data") ?
-      200 : fetcher->GetResponseCode();
-  if (http_response_code != 200) {
-    (callback.get())(original_url, http_response_code, nil);
-    return;
-  }
-
-  std::string response;
-  if (!fetcher->GetResponseAsString(&response)) {
-    (callback.get())(original_url, http_response_code, nil);
-    return;
-  }
-
-  // Create a NSData from the returned data and notify the callback.
-  base::scoped_nsobject<NSData> data([[NSData alloc]
-      initWithBytes:reinterpret_cast<const unsigned char*>(response.data())
-             length:response.size()]);
-
-  if (fetcher->GetResponseHeaders()) {
-    std::string mime_type;
-    fetcher->GetResponseHeaders()->GetMimeType(&mime_type);
-    if (mime_type == kWEBPMimeType) {
-      base::PostTaskAndReplyWithResult(task_runner_.get(),
-                                       FROM_HERE,
-                                       base::Bind(&DecodeWebpImage, data),
-                                       base::Bind(&ImageFetcher::RunCallback,
-                                                  weak_factory_.GetWeakPtr(),
-                                                  callback,
-                                                  original_url,
-                                                  http_response_code));
-      return;
-    }
-  }
-  (callback.get())(original_url, http_response_code, data);
-}
-
-void ImageFetcher::RunCallback(
-    const base::mac::ScopedBlock<ImageFetchedCallback>& callback,
-    const GURL& url,
-    int http_response_code,
-    NSData* data) {
-  (callback.get())(url, http_response_code, data);
-}
-
-void ImageFetcher::SetRequestContextGetter(
-    const scoped_refptr<net::URLRequestContextGetter>& request_context_getter) {
-  request_context_getter_ = request_context_getter;
-}