libchromeos: Switch http Response to use streams

Make the response data of an HTTP request to use stream interface.

BUG=None
TEST=`FEATURES=test emerge-link libchromeos`

Change-Id: I4d0e427e90f154a83ffd75973b4c211a989c1993
Reviewed-on: https://chromium-review.googlesource.com/265068
Trybot-Ready: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/metrics/uploader/sender_http.cc b/metrics/uploader/sender_http.cc
index 8e89b6e..8488b66 100644
--- a/metrics/uploader/sender_http.cc
+++ b/metrics/uploader/sender_http.cc
@@ -28,7 +28,7 @@
       headers,
       chromeos::http::Transport::CreateDefault(),
       &error);
-  if (!response || response->GetDataAsString() != "OK") {
+  if (!response || response->ExtractDataAsString() != "OK") {
     if (error) {
       DLOG(ERROR) << "Failed to send data: " << error->GetMessage();
     }