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

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

Index: chrome/browser/ui/cocoa/extensions/device_permissions_dialog_controller.mm
diff --git a/chrome/browser/ui/cocoa/extensions/device_permissions_dialog_controller.mm b/chrome/browser/ui/cocoa/extensions/device_permissions_dialog_controller.mm
index 852fbba7969c8be8e7451cd09e513bb0895e0e97..06c1aa39493f5983a60d2cba61719dc02c220972 100644
--- a/chrome/browser/ui/cocoa/extensions/device_permissions_dialog_controller.mm
+++ b/chrome/browser/ui/cocoa/extensions/device_permissions_dialog_controller.mm
@@ -9,12 +9,12 @@
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/extensions/api/chrome_device_permissions_prompt.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/device_permissions_view_controller.h"
 #include "components/web_modal/web_contents_modal_dialog_manager.h"
 #include "device/usb/usb_device.h"
+#include "ui/base/material_design/material_design_controller.h"
 
 using extensions::DevicePermissionsPrompt;
 
@@ -57,7 +57,7 @@ void DevicePermissionsDialogController::OnConstrainedWindowClosed(
 }
 
 void ChromeDevicePermissionsPrompt::ShowDialog() {
-  if (chrome::ToolkitViewsWebUIDialogsEnabled())
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial())
     return ChromeDevicePermissionsPrompt::ShowDialogViews();
   web_modal::WebContentsModalDialogManager* manager =
       web_modal::WebContentsModalDialogManager::FromWebContents(web_contents());