Autofill card unmasking prompt - Make "verifying..." message an overlay

ui/views/layout/fill_layout.h

 // Copyright (c) 2011 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_LAYOUT_FILL_LAYOUT_H_
 #define UI_VIEWS_LAYOUT_FILL_LAYOUT_H_
 
 #include "base/compiler_specific.h"
 #include "ui/views/layout/layout_manager.h"
 #include "ui/views/view.h"
 
 namespace views {
 
 ///////////////////////////////////////////////////////////////////////////////
 //
 // FillLayout
-//  A simple LayoutManager that causes the associated view's one child to be
-//  sized to match the bounds of its parent.
+//  A simple LayoutManager that causes the associated view's children to be
+//  sized to match the bounds of its parent. Multiple children are allowed,
+//  but only the first child will have any bearing on the preferred size.
 //
 ///////////////////////////////////////////////////////////////////////////////
 class VIEWS_EXPORT FillLayout : public LayoutManager {
  public:
   FillLayout();
   ~FillLayout() override;
 
   // Overridden from LayoutManager:
   void Layout(View* host) override;
   gfx::Size GetPreferredSize(const View* host) const override;
   int GetPreferredHeightForWidth(const View* host, int width) const override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FillLayout);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_LAYOUT_FILL_LAYOUT_H_