[Dice] Parse the Dice response header

chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc

Index: chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
diff --git a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
index 57fd85caa950166ca0ce15a16bb28b99cf48b3e3..3ebbe67499f10ff3898ada7c4bc3273c413666af 100644
--- a/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
+++ b/chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc
@@ -844,6 +844,9 @@ void ChromeResourceDispatcherHostDelegate::OnRequestRedirected(
   // native profile management UI is built on top of it.
   signin::FixAccountConsistencyRequestHeader(
       request, redirect_url, io_data, info->GetChildID(), info->GetRouteID());
+#if !defined(OS_IOS) && !defined(OS_ANDROID)
+  signin::ProcessDiceResponseHeaderIfExists(request, io_data);

[msarda, 2017/06/12 11:52:21]

It looks like the Mirror response header (ManageAccounts) is processed when a
response is received - see
https://cs.chromium.org/chromium/src/chrome/browser/loader/chrome_resource_di...

Why do we need to process the Dice response header on a redirect? Do we also
need to process it on a response?

[droger, 2017/06/12 12:39:14]

The Dice header is only seen on redirects currently.

We could call the function on responses as well, if we want to catch it if Gaia
changes the flow on their end, but I don't know if this is needed.

[msarda, 2017/06/12 14:03:42]

I think we're basically adding too much logic for sign-in header processing in
ChromeResourceDispatcherHostDelegate, but I am not an owner of
ChromeResourceDispatcherHostDelegate, so I do not know how much they care about
this. It may be good to just call the sign-in header helper once from here and
the header helper to do whatever it needs to do when a redirect occurs. WDYT?

[droger, 2017/06/12 16:12:58]

I understand. I merged the Dice and Mirror function. That way, if we need to
change the behavior in the future, we should not need to touch this file again.

+#endif
 
   if (io_data->loading_predictor_observer()) {
     io_data->loading_predictor_observer()->OnRequestRedirected(