Code: void WriteFromUrlOperation::Download(const base::Closure& continuation) {
  DCHECK_CURRENTLY_ON(BrowserThread::FILE);

  if (IsCancelled()) {
    return;
  }

  download_continuation_ = continuation;
 
   SetStage(image_writer_api::STAGE_DOWNLOAD);
 
  url_fetcher_ = net::URLFetcher::Create(url_, net::URLFetcher::GET, this);
 
   url_fetcher_->SetRequestContext(request_context_);
   url_fetcher_->SaveResponseToFileAtPath(
      image_path_, BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE));

  AddCleanUpFunction(
      base::Bind(&WriteFromUrlOperation::DestroyUrlFetcher, this));

  url_fetcher_->Start();
}

Vulnerability Type: DoS 
CWE ID: 
Summary: Use-after-free vulnerability in the GPU process implementation in Google Chrome before 44.0.2403.89 allows remote attackers to cause a denial of service or possibly have unspecified other impact by leveraging the continued availability of a GPUChannelHost data structure during Blink shutdown, related to content/browser/gpu/browser_gpu_channel_host_factory.cc and content/renderer/render_thread_impl.cc.
Commit Message: Network traffic annotation added to extensions::image_writer::WriteFromUrlOperation.

Network traffic annotation is added to network request of extensions::image_writer::WriteFromUrlOperation.

BUG=656607

Review-Url: https://codereview.chromium.org/2691963002
Cr-Commit-Position: refs/heads/master@{#451456}