net: Allow URLFetcher users to inject custom URLFetcherResponseWriter

net/url_request/test_url_fetcher_factory.cc

Index: net/url_request/test_url_fetcher_factory.cc
diff --git a/net/url_request/test_url_fetcher_factory.cc b/net/url_request/test_url_fetcher_factory.cc
index d080f50675d72615b53e9ff9dd07c2d91581f6ed..e4a47d7728080adf5fbcfb14ffb6bd4e0d76b21c 100644
--- a/net/url_request/test_url_fetcher_factory.cc
+++ b/net/url_request/test_url_fetcher_factory.cc
@@ -14,6 +14,7 @@
 #include "net/http/http_response_headers.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_fetcher_impl.h"
+#include "net/url_request/url_fetcher_response_writer.h"
 #include "net/url_request/url_request_status.h"
 
 namespace net {
@@ -147,6 +148,10 @@ void TestURLFetcher::SaveResponseToTemporaryFile(
     scoped_refptr<base::TaskRunner> file_task_runner) {
 }
 
+void TestURLFetcher::SaveResponseWithWriter(
+    scoped_ptr<URLFetcherResponseWriter> response_writer) {
+}
+
 HttpResponseHeaders* TestURLFetcher::GetResponseHeaders() const {
   return fake_response_headers_.get();
 }