Fix bug where the BinaryUploadService always has empty responses

This CL also adds a basic test for this.

Bug: 980784
Change-Id: Ic8696ef13811cf2cc0135268966ee47c04c4185f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1769235
Auto-Submit: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Commit-Queue: Varun Khaneja <vakh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690115}

chrome/browser/safe_browsing/download_protection/binary_upload_service.cc

@@ -231,7 +231,7 @@ void BinaryUploadService::OnTimeout(Request* request) {
 void BinaryUploadService::FinishRequest(Request* request,
                                         Result result,
                                         DeepScanningClientResponse response) {
-  request->FinishRequest(result, DeepScanningClientResponse());
+  request->FinishRequest(result, response);
   active_requests_.erase(request);
   active_timers_.erase(request);
   active_uploads_.erase(request);

chrome/browser/safe_browsing/download_protection/binary_upload_service_unittest.cc

@@ -232,6 +232,9 @@ TEST_F(BinaryUploadServiceTest, HoldsScanResponsesUntilAllReady) {
   response.mutable_malware_scan_verdict();
   ReceiveMessageForRequest(raw_request, response);
   content::RunAllTasksUntilIdle();
+
+  EXPECT_TRUE(scanning_response.has_dlp_scan_verdict());
+  EXPECT_TRUE(scanning_response.has_malware_scan_verdict());
   EXPECT_EQ(scanning_result, BinaryUploadService::Result::SUCCESS);
 }