URLFetcher won't call delegate until file is closed.

net/url_request/url_fetcher_response_writer.cc

Index: net/url_request/url_fetcher_response_writer.cc
diff --git a/net/url_request/url_fetcher_response_writer.cc b/net/url_request/url_fetcher_response_writer.cc
index cb30dad8089efd6acd2d699126782cce3d147c45..e56f34c201912f3dda9a1c761e04edf130ad15f9 100644
--- a/net/url_request/url_fetcher_response_writer.cc
+++ b/net/url_request/url_fetcher_response_writer.cc
@@ -102,8 +102,19 @@ int URLFetcherFileWriter::Write(IOBuffer* buffer,
 }
 
 int URLFetcherFileWriter::Finish(const CompletionCallback& callback) {
+  int result = file_stream_->Close(base::Bind(
+      &URLFetcherFileWriter::CloseComplete,
+      weak_factory_.GetWeakPtr(), callback));
+  if (result != ERR_IO_PENDING)
+    file_stream_.reset();
+  return result;
+}
+
+void URLFetcherFileWriter::CloseComplete(const CompletionCallback& callback,
+                                         int result) {
+  // Either we closed the file or we can't; either way destroy the file_stream.

[mmenke, 2013/09/11 15:16:11]

nit:  Some people strongly object to "We" in comments, due to ambiguity. 
Suggest something along the lines of "Either the close operation succeeded or
failed; ...."

[mmenke, 2013/09/11 15:16:11]

nit:  Either "destroy the FileStream" or "destroy |file_stream_|" (|| around
class members variables isn't required by Google style, but it's the style used
in the header, so should be consistent).

[waffles, 2013/09/11 19:54:48]

Done.

[waffles, 2013/09/11 19:54:48]

Done.

   file_stream_.reset();
-  return OK;
+  callback.Run(result);
 }
 
 void URLFetcherFileWriter::DidWrite(const CompletionCallback& callback,