Check response code before writing blob to file.

webkit/fileapi/file_writer_delegate.cc

Index: webkit/fileapi/file_writer_delegate.cc
diff --git a/webkit/fileapi/file_writer_delegate.cc b/webkit/fileapi/file_writer_delegate.cc
index 4bd1fc3ca51f948cb46752fb58518f057fa8c1d1..c2de08160fc803097c438c9d6a9c4dfe5fca029d 100644
--- a/webkit/fileapi/file_writer_delegate.cc
+++ b/webkit/fileapi/file_writer_delegate.cc
@@ -169,7 +169,7 @@ void FileWriterDelegate::OnResponseStarted(net::URLRequest* request) {
   // file_stream_->Seek() blocks the IO thread.
   // See http://crbug.com/75548.
   base::ThreadRestrictions::ScopedAllowIO allow_io;
-  if (!request->status().is_success()) {
+  if (!request->status().is_success() || request->GetResponseCode() != 200) {

[ericu, 2012/01/05 05:47:20]

Why is is_success true here, if the blob wasn't valid?
[Sorry--I'm away from my workstation and can't easily look that up.]

[tzik, 2012/01/05 06:59:45]

Looking at other use of URLRequestStatus, !is_success() seems to mean error on
lower layer. e.g. failed to connect to server.
Errors on upper layer (like 404) should be caught in response code.

If blob is invalid, status code is set to 404 and content of the response is
empty in current impl.
(In case of HTTP, if a resource is not found, response code is set to 404 and
content of response can be non empty error page.)

     OnError(base::PLATFORM_FILE_ERROR_FAILED);
     return;
   }