Move web modal dialog manager files into the constrained_window component.

components/constrained_window/show_modal_dialog_cocoa.cc

+// 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 <memory>
+
+#include "components/constrained_window/constrained_window_views.h"
+#include "components/web_modal/single_web_contents_dialog_manager.h"
+#include "components/web_modal/web_contents_modal_dialog_manager.h"
+#include "content/public/browser/web_contents.h"
+#include "ui/gfx/native_widget_types.h"
+
+// TODO(patricialor): This is a layering violation and should be deleted.
+// Currently it's needed because on Cocoa, the dialog needs to be shown with a
+// SingleWebContentsDialogManagerViewsMac, which depends on things inside
+// chrome/browser/ui/cocoa/constrained_window/* and thus can't be moved out into
+// components/constrained_window/*. Instead, to get this to work, the
+// CreateNativeWebModalManager() method is declared in the web_modal component,
+// but defined outside of that in c/b/u/cocoa/.
+
+namespace constrained_window {
+
+void ShowModalDialog(gfx::NativeWindow dialog,
+                     content::WebContents* initiator_web_contents) {
+  web_modal::WebContentsModalDialogManager* manager =
+      web_modal::WebContentsModalDialogManager::FromWebContents(
+          initiator_web_contents);
+  std::unique_ptr<web_modal::SingleWebContentsDialogManager> dialog_manager(
+      web_modal::WebContentsModalDialogManager::CreateNativeWebModalManager(
+          dialog, manager));
+  manager->ShowDialogWithManager(dialog, std::move(dialog_manager));
+}
+
+}  // namespace constrained_window