Glue parallel download job and download file together.

content/browser/download/download_job.cc

Index: content/browser/download/download_job.cc
diff --git a/content/browser/download/download_job.cc b/content/browser/download/download_job.cc
index 4da7eb429ae6eca4a6b880e8924dbe5f79e7a054..400a3fde9aa58c8f14f2e872d4fce1dc100c35bd 100644
--- a/content/browser/download/download_job.cc
+++ b/content/browser/download/download_job.cc
@@ -4,7 +4,10 @@
 
 #include "content/browser/download/download_job.h"
 
+#include "base/bind_helpers.h"
+#include "content/browser/download/download_file.h"
 #include "content/browser/download/download_item_impl.h"
+#include "content/public/browser/browser_thread.h"
 
 namespace content {
 
@@ -25,4 +28,25 @@ void DownloadJob::StartDownload() const {
   download_item_->StartDownload();
 }
 
+void DownloadJob::AddByteStream(std::unique_ptr<ByteStreamReader> stream_reader,
+                                int64_t offset,
+                                int64_t length) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DownloadFile* download_file = download_item_->download_file_.get();
+  if (!download_file) {
+    // TODO(xingliu): Handle early and late incoming streams, see crbug/702683.
+    VLOG(1) << "Download file is released when byte stream arrived. Discard "
+               "the byte stream.";
+    return;
+  }
+
+  // download_file_ is owned by download_item_ on the UI thread and is always
+  // deleted on the FILE thread after download_file_ is nulled out.
+  // So it's safe to use base::Unretained here.
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&DownloadFile::AddByteStream, base::Unretained(download_file),
+                 base::Passed(&stream_reader), offset, length));
+}
+
 }  // namespace content