Add VLOG in registration request

I can't repro locally nor using mb tool to repro. mb tool can
only launch jobs in chromium.tests pool which is a different
pool than internal bots.
I hope with the android id logged, we can find out what's going
on on the server side.

Bug: 1043347
Change-Id: I70ac3005b0b568284a18d76b35dee160d27c00b7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2031537Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Sven Zheng <svenzheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737472}

google_apis/gcm/engine/registration_request.cc

@@ -183,8 +183,9 @@ void RegistrationRequest::Start() {
   std::string body;
   BuildRequestBody(&body);
 
-  DVLOG(1) << "Performing registration for: " << request_info_.app_id();
-  DVLOG(1) << "Registration request: " << body;
+  // TODO(crbug.com/1043347): Change back to DVLOG when the bug is resolved.
+  VLOG(1) << "Performing registration for: " << request_info_.app_id();
+  VLOG(1) << "Registration request: " << body;
   url_loader_ =
       network::SimpleURLLoader::Create(std::move(request), traffic_annotation);
   url_loader_->AttachStringForUpload(body, kRegistrationRequestContentType);