Implement "pinned" mode in ash.

ash/accelerators/accelerator_controller.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/accelerators/accelerator_controller.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <utility>
@@ skipping 1398 matching lines @@
 }
 
 bool AcceleratorController::ShouldActionConsumeKeyEvent(
     AcceleratorAction action) {
   // Adding new exceptions is *STRONGLY* discouraged.
   return true;
 }
 
 AcceleratorController::AcceleratorProcessingRestriction
 AcceleratorController::GetAcceleratorProcessingRestriction(int action) {
+  if (WmShell::Get()->IsPinned() &&
+      reserved_actions_.find(action) == reserved_actions_.end()) {
+    return RESTRICTION_PREVENT_PROCESSING_AND_PROPAGATION;
+  }
   ash::Shell* shell = ash::Shell::GetInstance();
   if (!shell->session_state_delegate()->IsActiveUserSessionStarted() &&
       actions_allowed_at_login_screen_.find(action) ==
           actions_allowed_at_login_screen_.end()) {
     return RESTRICTION_PREVENT_PROCESSING;
   }
   if (shell->session_state_delegate()->IsScreenLocked() &&
       actions_allowed_at_lock_screen_.find(action) ==
           actions_allowed_at_lock_screen_.end()) {
     return RESTRICTION_PREVENT_PROCESSING;
@@ skipping 22 matching lines @@
 }
 
 void AcceleratorController::SetKeyboardBrightnessControlDelegate(
     std::unique_ptr<KeyboardBrightnessControlDelegate>
         keyboard_brightness_control_delegate) {
   keyboard_brightness_control_delegate_ =
       std::move(keyboard_brightness_control_delegate);
 }
 
 }  // namespace ash