Only exclude workarea from touch-exploration with active shell-surface

ash/ash_touch_exploration_manager_chromeos.h

Index: ash/ash_touch_exploration_manager_chromeos.h
diff --git a/ash/ash_touch_exploration_manager_chromeos.h b/ash/ash_touch_exploration_manager_chromeos.h
index f124ab8aa549d9217f1d84f0d4d639b20b51de49..63afdeaca1354a8eef75e4c48aa34d2d8fdcc42e 100644
--- a/ash/ash_touch_exploration_manager_chromeos.h
+++ b/ash/ash_touch_exploration_manager_chromeos.h
@@ -9,6 +9,7 @@
 
 #include "ash/ash_export.h"
 #include "ash/common/system/accessibility_observer.h"
+#include "ash/common/wm_display_observer.h"
 #include "base/macros.h"
 #include "ui/chromeos/touch_exploration_controller.h"
 #include "ui/wm/public/activation_change_observer.h"
@@ -27,6 +28,7 @@ class RootWindowController;
 class ASH_EXPORT AshTouchExplorationManager
     : public AccessibilityObserver,
       public ui::TouchExplorationControllerDelegate,
+      public ash::WmDisplayObserver,
       public aura::client::ActivationChangeObserver {
  public:
   explicit AshTouchExplorationManager(
@@ -46,6 +48,9 @@ class ASH_EXPORT AshTouchExplorationManager
   void PlayEnterScreenEarcon() override;
   void HandleAccessibilityGesture(ui::AXGesture gesture) override;
 
+  // ash::WmDisplayObserver overrides:
+  void OnDisplayConfigurationChanged() override;

[oshima, 2016/09/30 20:59:59]

can you use display::DisplayObserver instead?

[erosky, 2016/09/30 22:39:55]

I was just asked to switch from that to be forward-compatible with WmShell. What
is the difference here (besides not know which display changed in this one)?

[oshima, 2016/09/30 23:48:15]

display::DisplayObserver is a platform independent API, while WmDisplayObserve
is used to bring up ash desktop environment.

[oshima, 2016/10/01 00:07:44]

Sorry I wasn't clear enough.

Please use gfx::Screen::GetScreen()->Add/RemoveObserver instead of using
adding/removing directly to/from DisplayManager as it's ash internal.

[erosky, 2016/10/01 00:17:07]

Done.

+
   // aura::client::ActivationChangeObserver overrides:
   void OnWindowActivated(
       aura::client::ActivationChangeObserver::ActivationReason reason,