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

ui/views/test/test_views.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_TEST_TEST_VIEWS_H_
 #define UI_VIEWS_TEST_TEST_VIEWS_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 28 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(StaticSizedView);
 };
 
 // A view that accomodates testing layouts that use GetHeightForWidth.
 class ProportionallySizedView : public View {
  public:
   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;
 
  private:
   // The multiplicative factor between width and height, i.e.
   // height = width * factor_.
   int factor_;
 
   // The width used as the preferred size. -1 if not used.
@@ skipping 51 matching lines @@
   std::map<ui::EventType, int> event_count_;
   int last_flags_;
   HandleMode handle_mode_;
 
   DISALLOW_COPY_AND_ASSIGN(EventCountView);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_TEST_TEST_VIEWS_H_