Stop chromevox audio and clear focus highlight on switch to arc app

ash/ash_touch_exploration_manager_chromeos.cc

 // Copyright 2014 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/ash_touch_exploration_manager_chromeos.h"
 
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/wm_shell.h"
 #include "ash/root_window_controller.h"
@@ skipping 103 matching lines @@
 
   const bool spoken_feedback_enabled =
       WmShell::Get()->accessibility_delegate()->IsSpokenFeedbackEnabled();
 
   if (!pass_through_surface && spoken_feedback_enabled &&
       !touch_exploration_controller_.get()) {
     touch_exploration_controller_.reset(new ui::TouchExplorationController(
         root_window_controller_->GetRootWindow(), this));
   } else if (!spoken_feedback_enabled || pass_through_surface) {
     touch_exploration_controller_.reset();
+    if (spoken_feedback_enabled) {
+      SilenceSpokenFeedback();
+      WmShell::Get()->accessibility_delegate()->ClearFocusHighlight();
+    }
   }
 }
 
 bool AshTouchExplorationManager::VolumeAdjustSoundEnabled() {
   return !base::CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kDisableVolumeAdjustSound);
 }
 
 }  // namespace ash