views: Make mouse state member variables private to Widget.

views/widget/widget.h

Index: views/widget/widget.h
diff --git a/views/widget/widget.h b/views/widget/widget.h
index 352a58b5536b2ff2be2be4972217a634bc9554d2..3a19cc3bf71aaa0cf2a7444fb672252d6408a015 100644
--- a/views/widget/widget.h
+++ b/views/widget/widget.h
@@ -625,7 +625,6 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
   // deliver them. Displaying a window may result in the system generating
   // duplicate move events even though the mouse hasn't moved.
   bool last_mouse_event_was_move_;
-  gfx::Point last_mouse_event_position_;
 
  private:
   friend class NativeTextfieldViewsTest;
@@ -731,6 +730,8 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
   // Tracks whether native widget has been initialized.
   bool native_widget_initialized_;
 
+  gfx::Point last_mouse_event_position_;
+
   DISALLOW_COPY_AND_ASSIGN(Widget);
 };