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

chrome/browser/ui/cocoa/website_settings/permission_prompt_impl_views_mac.mm

 // Copyright 2016 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 "base/memory/ptr_util.h"
 #include "chrome/browser/ui/browser.h"
-#include "chrome/browser/ui/browser_dialogs.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_window.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #import "chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h"
 #import "chrome/browser/ui/cocoa/website_settings/permission_bubble_cocoa.h"
 #import "chrome/browser/ui/cocoa/website_settings/permission_bubble_controller.h"
 #include "chrome/browser/ui/views/website_settings/permission_prompt_impl.h"
 #import "ui/base/cocoa/cocoa_base_utils.h"
+#include "ui/base/material_design/material_design_controller.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
 
 // Implementation of PermissionPromptImpl's anchor methods for Cocoa
 // browsers. In Cocoa browsers there is no parent views::View for the permission
 // bubble, so these methods supply an anchor point instead.
 
 views::View* PermissionPromptImpl::GetAnchorView() {
   return nullptr;
 }
 
 gfx::Point PermissionPromptImpl::GetAnchorPoint() {
   return gfx::ScreenPointFromNSPoint(
       [PermissionBubbleController getAnchorPointForBrowser:browser_]);
 }
 
 views::BubbleBorder::Arrow PermissionPromptImpl::GetAnchorArrow() {
   return views::BubbleBorder::TOP_LEFT;
 }
 
 // static
 std::unique_ptr<PermissionPrompt> PermissionPrompt::Create(
     content::WebContents* web_contents) {
-  if (chrome::ToolkitViewsWebUIDialogsEnabled())
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial()) {
     return base::WrapUnique(new PermissionPromptImpl(
         chrome::FindBrowserWithWebContents(web_contents)));
+  }
   return base::MakeUnique<PermissionBubbleCocoa>(
       chrome::FindBrowserWithWebContents(web_contents));
 }