MacViews: Consolidate flags. Just use --secondary-ui-md to enable MacViews.

chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa.mm

Index: chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa.mm b/chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa.mm
index a4b9d07171a9abd3b94c7936bc8c7bc21744d27f..85bdb71ecdbf63c23f02d61b54cff1b9d31fe972 100644
--- a/chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa.mm
+++ b/chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa.mm
@@ -10,11 +10,11 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chooser_controller/chooser_controller.h"
 #include "chrome/browser/extensions/chrome_extension_chooser_dialog.h"
-#include "chrome/browser/ui/browser_dialogs.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_sheet.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_window.h"
 #import "chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa_controller.h"
 #include "components/web_modal/web_contents_modal_dialog_manager.h"
+#include "ui/base/material_design/material_design_controller.h"
 
 ChooserDialogCocoa::ChooserDialogCocoa(
     content::WebContents* web_contents,
@@ -51,9 +51,10 @@ void ChooserDialogCocoa::Dismissed() {
 
 void ChromeExtensionChooserDialog::ShowDialog(
     std::unique_ptr<ChooserController> chooser_controller) const {
-  if (chrome::ToolkitViewsWebUIDialogsEnabled())
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial()) {
     return ChromeExtensionChooserDialog::ShowDialogImpl(
         std::move(chooser_controller));
+  }
 
   web_modal::WebContentsModalDialogManager* manager =
       web_modal::WebContentsModalDialogManager::FromWebContents(web_contents_);