MacViews: Remove constrained window dependencies for certificate viewer.

components/constrained_window/native_web_contents_modal_dialog_manager_views_mac.h

+// 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 "components/constrained_window/native_web_contents_modal_dialog_manager_views.h"
+
+namespace web_modal {
+class SingleWebContentsDialogManagerDelegate;
+}
+
+namespace constrained_window {
+
+// Class for parenting a Mac Cocoa sheet on a views tab modal dialog off of a
+// views browser, e.g. for tab-modal Cocoa sheets. Since Cocoa sheets are modal
+// to the parent window, the sheet is instead parented to an invisible views
+// overlay window which is tab-modal.
+class NativeWebContentsModalDialogManagerViewsMac
+    : public NativeWebContentsModalDialogManagerViews {
+ public:
+  NativeWebContentsModalDialogManagerViewsMac(
+      gfx::NativeWindow dialog,
+      web_modal::SingleWebContentsDialogManagerDelegate* native_delegate);
+
+  // NativeWebContentsModalDialogManagerViews:
+  void OnPositionRequiresUpdate() override;
+  void ShowWidget(views::Widget* widget) override;
+  void HideWidget(views::Widget* widget) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NativeWebContentsModalDialogManagerViewsMac);
+};
+
+}  // namespace constrained_window