Convert TrayEventFilter to wm common types

ash/common/wm_shell.h

Index: ash/common/wm_shell.h
diff --git a/ash/common/wm_shell.h b/ash/common/wm_shell.h
index 59472a89b76f1b2995b842f328c1631c4256d325..78ee00d2744ef22abecc1d6e38367f00db1de364 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -17,6 +17,10 @@ namespace gfx {
 class Rect;
 }
 
+namespace views {
+class PointerWatcher;
+}
+
 namespace ash {
 
 class AccessibilityDelegate;
@@ -145,6 +149,9 @@ class ASH_EXPORT WmShell {
   virtual void AddShellObserver(ShellObserver* observer) = 0;
   virtual void RemoveShellObserver(ShellObserver* observer) = 0;
 
+  virtual void AddPointerWatcher(views::PointerWatcher* watcher) = 0;
+  virtual void RemovePointerWatcher(views::PointerWatcher* watcher) = 0;
+
 #if defined(OS_CHROMEOS)
   // TODO(jamescook): Remove this when VirtualKeyboardController has been moved.
   virtual void ToggleIgnoreExternalKeyboard() = 0;