arc: Prevent showing Opt-in UI when it is not expected.

chrome/browser/chromeos/arc/arc_auth_service.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/arc/arc_auth_service.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 391 matching lines @@
   observer_list_.AddObserver(observer);
 }
 
 void ArcAuthService::RemoveObserver(Observer* observer) {
   DCHECK(thread_checker.Get().CalledOnValidThread());
   observer_list_.RemoveObserver(observer);
 }
 
 void ArcAuthService::CloseUI() {
   FOR_EACH_OBSERVER(Observer, observer_list_, OnOptInUIClose());
+  SetUIPage(UIPage::NO_PAGE, base::string16());
   if (!disable_ui_for_testing)

[khmel, 2016/04/23 00:34:40]

I have one more question. There is an idea to prevent pinning this app at all.
Do you know if any legacy functionality for this? I tried to find but seems it
is not available. If not I would say it is too hack-y to implement special for
this case. 

[xiyuan, 2016/04/25 21:14:35]

Have you checked AppListControllerDelegateAsh::GetPinnable[1]? Maybe we should
check also check Extension::ShouldDisplayInAppLauncher and returns NO_PIN if the
exntension does not display in launcher?

[1]:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...

[khmel, 2016/04/26 16:37:10]

This might be good point to insert this check.

     ArcAuthNotification::Hide();
 }
 
 void ArcAuthService::SetUIPage(UIPage page, const base::string16& status) {
   ui_page_ = page;
   ui_page_status_ = status;
   FOR_EACH_OBSERVER(Observer, observer_list_,
                     OnOptInUIShowPage(ui_page_, ui_page_status_));
 }
 
@@ skipping 109 matching lines @@
       return os << kStateFetchingCode;
     case ArcAuthService::State::ACTIVE:
       return os << kStateActive;
     default:
       NOTREACHED();
       return os;
   }
 }
 
 }  // namespace arc