Use IOSImageDataFetcherWrapper for favicon

ios/web/web_state/web_state_impl.mm

Index: ios/web/web_state/web_state_impl.mm
diff --git a/ios/web/web_state/web_state_impl.mm b/ios/web/web_state/web_state_impl.mm
index 864fee37ca2eef90ab3681eb6bae139bd29132b4..01bc800b0b1ff302d751ad997e5e1e6f8b9686df 100644
--- a/ios/web/web_state/web_state_impl.mm
+++ b/ios/web/web_state/web_state_impl.mm
@@ -565,40 +565,6 @@ bool WebStateImpl::ShouldAllowResponse(NSURLResponse* response) {
 
 #pragma mark - RequestTracker management
 
-int WebStateImpl::DownloadImage(
-    const GURL& url,
-    bool is_favicon,
-    uint32_t max_bitmap_size,
-    bool bypass_cache,
-    const ImageDownloadCallback& callback) {
-  // |is_favicon| specifies whether the download of the image occurs with
-  // cookies or not. Currently, only downloads without cookies are supported.
-  // |bypass_cache| is ignored since the downloads never go through a cache.
-  DCHECK(is_favicon);
-
-  static int downloaded_image_count = 0;
-  int local_download_id = ++downloaded_image_count;
-  __block web::WebState::ImageDownloadCallback local_image_callback = callback;
-  __block GURL local_url(url);
-  ImageFetchedCallback local_callback =
-      ^(const GURL&, const int response_code, NSData* data) {
-        std::vector<SkBitmap> frames;
-        std::vector<gfx::Size> sizes;
-        if (data) {
-          frames = skia::ImageDataToSkBitmaps(data);
-          for (auto& frame : frames) {
-            sizes.push_back(gfx::Size(frame.width(), frame.height()));
-          }
-        }
-        if (response_code != net::URLFetcher::RESPONSE_CODE_INVALID) {
-          local_image_callback.Run(local_download_id, response_code, local_url,
-                                   frames, sizes);
-        }
-      };
-  image_fetcher_->StartDownload(url, local_callback);
-  return downloaded_image_count;
-}
-
 service_manager::InterfaceRegistry* WebStateImpl::GetMojoInterfaceRegistry() {
   if (!mojo_interface_registry_) {
     mojo_interface_registry_ =