Handle early pause, cancel for parallel requests.

content/browser/download/download_worker.cc

Index: content/browser/download/download_worker.cc
diff --git a/content/browser/download/download_worker.cc b/content/browser/download/download_worker.cc
index 5f65d9eb82c2e9882b905e5f284fbdd41d8f667d..e677352ebd0709d9abb82936bec7d60f8daffdd6 100644
--- a/content/browser/download/download_worker.cc
+++ b/content/browser/download/download_worker.cc
@@ -77,6 +77,13 @@ void DownloadWorker::OnUrlDownloaderStarted(
   // |callback| is not used in subsequent requests.
   DCHECK(callback.is_null());
 
+  // Destroy the request if user canceled.
+  if (delegate_->IsCanceled()) {
+    VLOG(kVerboseLevel) << "Byte stream arrived after user cancel the request.";
+    create_info->request_handle->CancelRequest();
+    return;
+  }
+
   // TODO(xingliu): Add the interrupt reason and metric data for precondition
   // failure. Make DownloadRequestCore know if it should return error if the
   // the server gives a different part of the content, e.g. "If-Match" return
@@ -90,8 +97,14 @@ void DownloadWorker::OnUrlDownloaderStarted(
   }
 
   request_handle_ = std::move(create_info->request_handle);
-  if (delegate_)
-    delegate_->OnByteStreamReady(this, std::move(stream_reader));
+
+  // Pause the stream if user paused, still push the stream reader to the sink.
+  if (delegate_->IsPaused()) {
+    VLOG(kVerboseLevel) << "Byte stream arrived after user pause the request.";
+    Pause();
+  }
+
+  delegate_->OnByteStreamReady(this, std::move(stream_reader));
 }
 
 void DownloadWorker::OnUrlDownloaderStopped(UrlDownloader* downloader) {