Improve error handling in FtpDirectoryListingResponseDelegate.

content/child/ftp_directory_listing_response_delegate.h

Index: content/child/ftp_directory_listing_response_delegate.h
diff --git a/content/child/ftp_directory_listing_response_delegate.h b/content/child/ftp_directory_listing_response_delegate.h
index 0d1a61f3e979cb27cdfee44180742cc0200a26bf..319cad0c4376b05846a00516b991b318d6275635 100644
--- a/content/child/ftp_directory_listing_response_delegate.h
+++ b/content/child/ftp_directory_listing_response_delegate.h
@@ -11,6 +11,7 @@
 #include <string>
 
 #include "base/macros.h"
+#include "base/strings/string_piece.h"
 #include "third_party/WebKit/public/platform/WebURLResponse.h"
 
 namespace blink {
@@ -31,14 +32,14 @@ class FtpDirectoryListingResponseDelegate {
   // The request has been canceled, so stop making calls to the client.
   void Cancel();
 
-  // Passed through from ResourceHandleInternal
+  // Called from WebURLLoaderImpl.
   void OnReceivedData(const char* data, int data_len);
-  void OnCompletedRequest();
+  void OnCompletedRequest(int error_code);
 
  private:
   void Init(const GURL& response_url);
 
-  void SendDataToClient(const std::string& data);
+  void SendDataToClient(base::StringPiece data);
 
   // Pointers to the client and associated loader so we can make callbacks as
   // we parse pieces of data.