Add user_info_ NULL check in case of guest mode.

ash/system/user/tray_user.cc

 // Copyright (c) 2012 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 "ash/system/user/tray_user.h"
 
 #include "ash/shell.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_item_view.h"
@@ skipping 213 matching lines @@
       return;
 
     container_->SetBoundsRect(gfx::Rect(size()));
     if (signout_) {
       gfx::Rect signout_bounds(signout_->GetPreferredSize());
       signout_bounds = bounds().Center(signout_bounds.size());
       signout_bounds.set_x(width() - signout_bounds.width() -
           kTrayPopupPaddingHorizontal);
       signout_->SetBoundsRect(signout_bounds);
 
-      gfx::Rect usercard_bounds(user_info_->GetPreferredSize());
-      usercard_bounds.set_width(signout_bounds.x());
-      user_info_->SetBoundsRect(usercard_bounds);
-    } else {
+      if (user_info_) {
+        gfx::Rect usercard_bounds(user_info_->GetPreferredSize());
+        usercard_bounds.set_width(signout_bounds.x());
+        user_info_->SetBoundsRect(usercard_bounds);
+      }

[sadrul, 2012/05/17 17:07:32]

I think what this will do is we will end up with empty space on the left, and an
exit button on the right. I think instead, the button should expand to fill up
the whole row.

[Jun Mukai, 2012/05/17 20:13:36]

Done.

+    } else if (user_info_) {
       user_info_->SetBoundsRect(gfx::Rect(size()));
     }
   }
 
   user::LoginStatus login_;
 
   TrayPopupTextButtonContainer* container_;
   views::View* user_info_;
   views::Label* username_;
   views::Label* email_;
@@ skipping 58 matching lines @@
 }
 
 void TrayUser::OnUserUpdate() {
   avatar_->SetImage(
       ash::Shell::GetInstance()->tray_delegate()->GetUserImage(),
       gfx::Size(kUserIconSize, kUserIconSize));
 }
 
 }  // namespace internal
 }  // namespace ash