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

ui/views/test/test_views.cc

 // 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.
 
 #include "ui/views/test/test_views.h"
 
 #include "ui/events/event.h"
 #include "ui/views/widget/native_widget_private.h"
 #include "ui/views/widget/widget.h"
 
@@ skipping 17 matching lines @@
 
 gfx::Size StaticSizedView::GetMaximumSize() const {
   return maximum_size_;
 }
 
 ProportionallySizedView::ProportionallySizedView(int factor)
     : factor_(factor), preferred_width_(-1) {}
 
 ProportionallySizedView::~ProportionallySizedView() {}
 
+void ProportionallySizedView::SetPreferredWidth(int width) {
+  preferred_width_ = width;
+  PreferredSizeChanged();
+}
+
 int ProportionallySizedView::GetHeightForWidth(int w) const {
   return w * factor_;
 }
 
 gfx::Size ProportionallySizedView::GetPreferredSize() const {
   if (preferred_width_ >= 0)
     return gfx::Size(preferred_width_, GetHeightForWidth(preferred_width_));
   return View::GetPreferredSize();
 }
 
@@ skipping 51 matching lines @@
 }
 
 void EventCountView::RecordEvent(ui::Event* event) {
   ++event_count_[event->type()];
   last_flags_ = event->flags();
   if (handle_mode_ == CONSUME_EVENTS)
     event->SetHandled();
 }
 
 }  // namespace views