MacViews: Use native certificate viewer in MacViews browser.

chrome/browser/ui/cocoa/create_native_web_modal_manager_cocoa.mm

+// Copyright 2015 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.
+
+#import "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_sheet.h"
+#import "chrome/browser/ui/cocoa/single_web_contents_dialog_manager_cocoa.h"
+#include "components/web_modal/web_contents_modal_dialog_manager.h"
+
+namespace web_modal {
+
+SingleWebContentsDialogManager*
+WebContentsModalDialogManager::CreateNativeWebModalManager(
+    gfx::NativeWindow dialog,
+    web_modal::SingleWebContentsDialogManagerDelegate* delegate) {
+  base::scoped_nsobject<CustomConstrainedWindowSheet> sheet(
+      [[CustomConstrainedWindowSheet alloc] initWithCustomWindow:dialog]);
+  return new SingleWebContentsDialogManagerCocoa(nullptr, sheet, delegate);
+}
+
+}  // namespace web_modal