[ash-md] Fixed TriView to relayout child Views when their preferred size changed.

ui/views/test/test_views.h

Index: ui/views/test/test_views.h
diff --git a/ui/views/test/test_views.h b/ui/views/test/test_views.h
index eaabcd0e0cdc108dfa5dd2f692ed073e0ec5d944..9097092ecc22630a4eecba12b0825d2e8e7a5dfd 100644
--- a/ui/views/test/test_views.h
+++ b/ui/views/test/test_views.h
@@ -46,7 +46,7 @@ class ProportionallySizedView : public View {
   explicit ProportionallySizedView(int factor);
   ~ProportionallySizedView() override;
 
-  void set_preferred_width(int width) { preferred_width_ = width; }
+  void SetPreferredWidth(int width);
 
   int GetHeightForWidth(int w) const override;
   gfx::Size GetPreferredSize() const override;