MacViews: Put wm window animation calls behind an interface.

ui/views/widget/widget.cc

Index: ui/views/widget/widget.cc
diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index 8cf11ffafca333f00ce45e83ad71ae5ff49816bb..74bd54bbed493cfb464feea9dfd5f31fa42cc0d4 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -519,6 +519,14 @@ void Widget::SetVisibilityChangedAnimationsEnabled(bool value) {
   native_widget_->SetVisibilityChangedAnimationsEnabled(value);
 }
 
+void Widget::SetVisibilityAnimationDuration(const base::TimeDelta& duration) {
+  native_widget_->SetVisibilityAnimationDuration(duration);
+}
+
+void Widget::SetVisibilityAnimationTransition(VisibilityTransition transition) {
+  native_widget_->SetVisibilityAnimationTransition(transition);
+}
+
 Widget::MoveLoopResult Widget::RunMoveLoop(
     const gfx::Vector2d& drag_offset,
     MoveLoopSource source,