Implement cycle window forward/backward by keyboard shortcuts.

ui/aura_shell/shell.cc

 // Copyright (c) 2011 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 "ui/aura_shell/shell.h"
 
+#include <algorithm>
+
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "ui/aura/aura_switches.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_types.h"
 #include "ui/aura_shell/activation_controller.h"
@@ skipping 261 matching lines @@
   if (workspace_controller_.get())
     workspace_controller_->ToggleOverview();
 }
 
 void Shell::ToggleAppList() {
   if (!app_list_.get())
     app_list_.reset(new internal::AppList);
   app_list_->SetVisible(!app_list_->IsVisible());
 }
 
+// Returns true if the screen is locked.
+bool Shell::IsScreenLocked() const {
+  const aura::Window* lock_screen_container = GetContainer(
+      internal::kShellWindowId_LockScreenContainer);
+  const aura::Window::Windows& lock_screen_windows =
+      lock_screen_container->children();
+  aura::Window::Windows::const_iterator lock_screen_it =
+      std::find_if(lock_screen_windows.begin(), lock_screen_windows.end(),
+                   std::mem_fun(&aura::Window::IsVisible));
+  if (lock_screen_it != lock_screen_windows.end())
+    return true;
+
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Shell, private:
 
 void Shell::EnableWorkspaceManager() {
   aura::Window* default_container =
       GetContainer(internal::kShellWindowId_DefaultContainer);
 
   workspace_controller_.reset(
       new internal::WorkspaceController(default_container));
   workspace_controller_->SetLauncherModel(launcher_->model());
   default_container->SetEventFilter(
       new internal::DefaultContainerEventFilter(default_container));
   default_container->SetLayoutManager(
       new internal::DefaultContainerLayoutManager(
           workspace_controller_->workspace_manager()));
 }
 
 }  // namespace aura_shell