Limit parallel download to http GET requests.

content/browser/download/download_create_info.h

Index: content/browser/download/download_create_info.h
diff --git a/content/browser/download/download_create_info.h b/content/browser/download/download_create_info.h
index 1f6c77316d7a3248cf2632a62135cb499a00cd02..1cac8e62794babfa13b6fc92f31b7d11f44145e9 100644
--- a/content/browser/download/download_create_info.h
+++ b/content/browser/download/download_create_info.h
@@ -136,6 +136,9 @@ struct CONTENT_EXPORT DownloadCreateInfo {
   // The HTTP connection type.
   net::HttpResponseInfo::ConnectionInfo connection_info;
 
+  // The HTTP request method.
+  std::string method;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(DownloadCreateInfo);
 };