net: Use SequencedTaskRunner for URLFetcherResponseWriter

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 ee52578420c54bedef425d19ff08843dfa650537..fd08a8df65e5004dcf6db221c15d43614894d4a2 100644
--- a/net/url_request/url_fetcher_response_writer.cc
+++ b/net/url_request/url_fetcher_response_writer.cc
@@ -6,7 +6,7 @@
 
 #include "base/file_util.h"
 #include "base/location.h"
-#include "base/task_runner.h"
+#include "base/sequenced_task_runner.h"
 #include "base/task_runner_util.h"
 #include "net/base/file_stream.h"
 #include "net/base/io_buffer.h"
@@ -50,7 +50,7 @@ URLFetcherStringWriter* URLFetcherStringWriter::AsStringWriter() {
 }
 
 URLFetcherFileWriter::URLFetcherFileWriter(
-    scoped_refptr<base::TaskRunner> file_task_runner,
+    scoped_refptr<base::SequencedTaskRunner> file_task_runner,
     const base::FilePath& file_path)
     : weak_factory_(this),
       file_task_runner_(file_task_runner),