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

ui/views/window/dialog_client_view.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 <algorithm>
 
 #include "build/build_config.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/button/blue_button.h"
+#include "ui/views/controls/button/checkbox.h"
 #include "ui/views/controls/button/custom_button.h"
 #include "ui/views/controls/button/label_button.h"
 #include "ui/views/controls/button/md_text_button.h"
 #include "ui/views/layout/grid_layout.h"
 #include "ui/views/layout/layout_provider.h"
 #include "ui/views/style/platform_style.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/dialog_delegate.h"
 
 namespace views {
@@ skipping 360 matching lines @@
   for (size_t view_index = 0; view_index < kNumButtons; ++view_index) {
     if (views[view_index]) {
       layout->AddView(views[view_index]);
       link[link_index++] = kViewToColumnIndex[view_index];
     } else {
       layout->SkipColumns(1);
     }
   }
 
   if (ui::MaterialDesignController::IsSecondaryUiMaterial()) {
-    // Only link the extra view column if it is a button.
-    if (views[0] && !CustomButton::AsCustomButton(views[0]))
+    // If |views[0]| is non-null, it is a visible |extra_view_| and its column
+    // will be in |link[0]|. Skip that if it is not a button, or if it is a
+    // Checkbox (which extends LabelButton). Otherwise, link everything.
+    bool skip_first_link =
+        views[0] && (!CustomButton::AsCustomButton(views[0]) ||
+                     views[0]->GetClassName() == Checkbox::kViewClassName);
+    if (skip_first_link)
       column_set->LinkColumnSizes(link[1], link[2], -1);
     else
       column_set->LinkColumnSizes(link[0], link[1], link[2], -1);
   }
   layout->AddPaddingRow(kFixed, insets.bottom());
 }
 
 void DialogClientView::SetupViews() {
   button_row_container_->RemoveAllChildViews(false /* delete children */);
   // If SetupLayout() "stored" a hidden |extra_view_| in |this|, ensure it can
   // be re-added to the layout when becoming visible.
   if (extra_view_)
     RemoveChildView(extra_view_);
 
   UpdateDialogButton(&ok_button_, ui::DIALOG_BUTTON_OK);
   UpdateDialogButton(&cancel_button_, ui::DIALOG_BUTTON_CANCEL);
 
   if (extra_view_)
     return;
 
   extra_view_ = GetDialogDelegate()->CreateExtraView();
   if (extra_view_)
     extra_view_->SetGroup(kButtonGroup);
 }
 
 }  // namespace views