Save response headers and return to the caller when receive a redirect but URL...

Save response headers and return to the caller when receive a redirect but URL fetcher stops on redirects.

Bug: 936350
Change-Id: I933f362c966676d4a6dbbc0704afd69851edc248
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2143652Reviewed-by: Eric Roman <eroman@chromium.org>
Commit-Queue: Zhongyi Shi <zhongyi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758047}

net/url_request/url_fetcher_core.cc

@@ -406,6 +406,7 @@ void URLFetcherCore::OnReceivedRedirect(URLRequest* request,
     stopped_on_redirect_ = true;
     url_ = redirect_info.new_url;
     response_code_ = request_->GetResponseCode();
+    response_headers_ = request_->response_headers();
     proxy_server_ = request_->proxy_server();
     was_cached_ = request_->was_cached();
     total_received_bytes_ += request_->GetTotalReceivedBytes();

net/url_request/url_fetcher_impl_unittest.cc

@@ -1185,6 +1185,9 @@ TEST_F(URLFetcherTest, StopOnRedirect) {
             delegate.fetcher()->GetStatus().status());
   EXPECT_THAT(delegate.fetcher()->GetStatus().error(), IsError(ERR_ABORTED));
   EXPECT_EQ(301, delegate.fetcher()->GetResponseCode());
+  ASSERT_TRUE(delegate.fetcher()->GetResponseHeaders());
+  EXPECT_TRUE(delegate.fetcher()->GetResponseHeaders()->HasHeaderValue(
+      "Location", std::string(kRedirectTarget)));
 }
 
 TEST_F(URLFetcherTest, ThrottleOnRepeatedFetches) {