arc: ARC loading progress should not be shown when started from OOBE.

chrome/browser/chromeos/arc/arc_support_host.h

Index: chrome/browser/chromeos/arc/arc_support_host.h
diff --git a/chrome/browser/chromeos/arc/arc_support_host.h b/chrome/browser/chromeos/arc/arc_support_host.h
index 9a33c41a17166439747d8b4cd5e7df56e72940a2..399815d0f2e2d18ab99644dc37e8a3408903108f 100644
--- a/chrome/browser/chromeos/arc/arc_support_host.h
+++ b/chrome/browser/chromeos/arc/arc_support_host.h
@@ -125,6 +125,9 @@ class ArcSupportHost : public arc::ArcSupportMessageHost::Observer,
   // TODO(hidehiko): Remove this exposure.
   UIPage ui_page() const { return ui_page_; }
 
+  // Returns true if message host is currently attached which means UI is shown.
+  bool has_message_host() const { return message_host_; }

[hidehiko, 2016/12/16 05:31:50]

Please do not expose anything about related to message_host_.
It is asynchronously connected, and this class is wrapping it to encapsulates
the asynchronous-ness.
IIUC, you do not need anymore?

[khmel, 2016/12/16 18:37:55]

It is needed, please see void ArcSessionManager::OnTermsOfServiceNegotiated(bool
accepted). This method starts Arc Loading progress. It is required for default
case but not required for OOBE case.

[hidehiko, 2016/12/19 15:49:44]

Oh I see. Then please use ui_page_, instead, for the page transition tracking.
Considering that we do want to remove it directly, maybe we'd like to have
another accessor, e.g. IsWindowOpened(), with comment about the timing issue
(the actual window opening/closing may be delayed).

[khmel, 2016/12/19 17:48:10]

I added parameter force_activate to ShowArcLoading. Hope this would work better.

+
   void SetRequestOpenAppCallbackForTesting(
       const RequestOpenAppCallback& callback);