Enable native accessible touch support inside of ARC

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/common/wm_window.h"
@@ skipping 117 matching lines @@
   }
 }
 
 void AshTouchExplorationManager::UpdateTouchExplorationState() {
   // Comes from components/exo/shell_surface.cc.
   const char kExoShellSurfaceWindowName[] = "ExoShellSurface";
 
   // See crbug.com/603745 for more details.
   const bool pass_through_surface =
       wm::GetActiveWindow() &&
-      wm::GetActiveWindow()->GetName() == kExoShellSurfaceWindowName;
+      wm::GetActiveWindow()->GetName() == kExoShellSurfaceWindowName &&
+      !base::CommandLine::ForCurrentProcess()->HasSwitch(

[reveman, 2017/03/13 16:59:58]

I think you also need to check that the shell surface is actually an arc shell
surface before you consider this option. You'll need to get the application id
and check that it has a "org.chromium.arc." prefix.

[David Tseng, 2017/03/16 20:00:37]

I modified the check above (which indicates a pass through surface) to directly
check the new window property for arc app type.

+          chromeos::switches::kEnableChromeVoxArcSupport);
+  ;
 
   const bool spoken_feedback_enabled =
       WmShell::Get()->accessibility_delegate()->IsSpokenFeedbackEnabled();
 
   if (!touch_accessibility_enabler_) {
     // Always enable gesture to toggle spoken feedback.
     touch_accessibility_enabler_.reset(new ui::TouchAccessibilityEnabler(
         root_window_controller_->GetRootWindow(), this));
   }
 
@@ skipping 18 matching lines @@
     touch_exploration_controller_.reset();
   }
 }
 
 bool AshTouchExplorationManager::VolumeAdjustSoundEnabled() {
   return !base::CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kDisableVolumeAdjustSound);
 }
 
 }  // namespace ash