Check if there is no window in LockSystemModalContainer when unlocked.

ash/shell.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/shell.h"
 
 #include <algorithm>
 #include <string>
 
 #include "ash/accelerators/focus_manager_factory.h"
@@ skipping 725 matching lines @@
        iter != controllers.end(); ++iter)
     (*iter)->UpdateAfterLoginStatusChange(status);
 }
 
 void Shell::OnAppTerminating() {
   FOR_EACH_OBSERVER(ShellObserver, observers_, OnAppTerminating());
 }
 
 void Shell::OnLockStateChanged(bool locked) {
   FOR_EACH_OBSERVER(ShellObserver, observers_, OnLockStateChanged(locked));
+  // Make sure that there is no system modal in Lock layer when unlocked.
+  if (!locked) {
+    std::vector<aura::Window*> containers = GetContainersFromAllRootWindows(
+        internal::kShellWindowId_LockSystemModalContainer,
+        GetPrimaryRootWindow());
+    for (std::vector<aura::Window*>::const_iterator iter = containers.begin();
+         iter != containers.end(); ++iter) {
+      DCHECK_EQ(0u, (*iter)->children().size());

[James Cook, 2013/08/09 19:08:03]

Do you want DCHECK or CHECK here?  Are you trying to find problems on actual
devices in the field?

If you stick with DCHECK, maybe wrap this code in #ifdef NDEBUG so we don't do
the loop iteration for a no-op DCHECK.

+    }
+  }
 }
 
 void Shell::CreateLauncher() {
   RootWindowControllerList controllers = GetAllRootWindowControllers();
   for (RootWindowControllerList::iterator iter = controllers.begin();
        iter != controllers.end(); ++iter)
     (*iter)->shelf()->CreateLauncher();
 }
 
 void Shell::ShowLauncher() {
@@ skipping 210 matching lines @@
 ////////////////////////////////////////////////////////////////////////////////
 // Shell, aura::client::ActivationChangeObserver implementation:
 
 void Shell::OnWindowActivated(aura::Window* gained_active,
                               aura::Window* lost_active) {
   if (gained_active)
     target_root_window_ = gained_active->GetRootWindow();
 }
 
 }  // namespace ash