Implement "pinned" mode in ash.

ash/wm/overview/window_selector_controller.cc

 // Copyright 2013 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/wm/overview/window_selector_controller.h"
 
 #include <vector>
 
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
@@ skipping 15 matching lines @@
 
 // static
 bool WindowSelectorController::CanSelect() {
   // Don't allow a window overview if the screen is locked or a modal dialog is
   // open or running in kiosk app session.
   SessionStateDelegate* session_state_delegate =
       WmShell::Get()->GetSessionStateDelegate();
   return session_state_delegate->IsActiveUserSessionStarted() &&
          !session_state_delegate->IsScreenLocked() &&
          !Shell::GetInstance()->IsSystemModalWindowOpen() &&
+         !WmShell::Get()->IsPinned() &&
          WmShell::Get()->system_tray_delegate()->GetUserLoginStatus() !=
              LoginStatus::KIOSK_APP;
 }
 
 void WindowSelectorController::ToggleOverview() {
   if (IsSelecting()) {
     OnSelectionEnded();
   } else {
     // Don't start overview if window selection is not allowed.
     if (!CanSelect())
@@ skipping 37 matching lines @@
 
 void WindowSelectorController::OnSelectionStarted() {
   if (!last_selection_time_.is_null()) {
     UMA_HISTOGRAM_LONG_TIMES(
         "Ash.WindowSelector.TimeBetweenUse",
         base::Time::Now() - last_selection_time_);
   }
 }
 
 }  // namespace ash