Don't allow Checkboxes to participate in equal-sized-buttons in Harmony dialogs.

ui/views/window/dialog_client_view_unittest.cc

 // Copyright (c) 2012 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/window/dialog_client_view.h"
 
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "ui/base/test/material_design_controller_test_api.h"
 #include "ui/base/ui_base_types.h"
+#include "ui/views/controls/button/checkbox.h"
 #include "ui/views/controls/button/label_button.h"
 #include "ui/views/style/platform_style.h"
 #include "ui/views/test/test_views.h"
 #include "ui/views/test/widget_test.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/dialog_delegate.h"
 
 namespace views {
 
 // Base class for tests. Also acts as the dialog delegate and contents view for
@@ skipping 360 matching lines @@
   // OK button should now match the bigger, cancel button.
   EXPECT_EQ(cancel_button_width, client_view()->ok_button()->width());
 
   // But not under non-MD.
   md_test_api.SetSecondaryUiMaterial(false);
   client_view()->UpdateDialogButtons();
   CheckContentsIsSetToPreferredSize();
   EXPECT_EQ(ok_button_only_width, client_view()->ok_button()->width());
   md_test_api.SetSecondaryUiMaterial(true);
 
-  // The extra view should also match, if it's a button.
+  // The extra view should also match, if it's a matching button type.
   LabelButton* extra_button = new LabelButton(nullptr, base::string16());
   SetExtraView(extra_button);
   CheckContentsIsSetToPreferredSize();
   EXPECT_EQ(cancel_button_width, extra_button->width());
 
   // Remove |extra_button| from the View hierarchy so that it can be replaced.
   delete extra_button;
 
+  // Checkbox extends LabelButton. It should not participate in linking.

[msw, 2017/05/03 18:21:02]

nit: "LabelButton, but it"

[tapted, 2017/05/04 00:31:11]

Done.

+  extra_button = new Checkbox(base::string16());
+  SetExtraView(extra_button);
+  CheckContentsIsSetToPreferredSize();
+  EXPECT_NE(cancel_button_width, extra_button->width());
+
+  // Remove |extra_button| from the View hierarchy so that it can be replaced.
+  delete extra_button;
+
   // Non-buttons should always be sized to their preferred size.
   View* boring_view = new StaticSizedView(gfx::Size(20, 20));
   SetExtraView(boring_view);
   CheckContentsIsSetToPreferredSize();
   EXPECT_EQ(20, boring_view->width());
 }
 
 }  // namespace views