Add a Cocoa version of the auto-dismissing dialog.

chrome/browser/ui/javascript_dialogs/javascript_dialog.h

Index: chrome/browser/ui/javascript_dialogs/javascript_dialog.h
diff --git a/chrome/browser/ui/javascript_dialogs/javascript_dialog.h b/chrome/browser/ui/javascript_dialogs/javascript_dialog.h
new file mode 100644
index 0000000000000000000000000000000000000000..3e10dadbcdacb6be716ef1dac261ab45f1b8d3bf
--- /dev/null
+++ b/chrome/browser/ui/javascript_dialogs/javascript_dialog.h
@@ -0,0 +1,32 @@
+// 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.
+
+#ifndef CHROME_BROWSER_UI_JAVASCRIPT_DIALOGS_JAVASCRIPT_DIALOG_H_
+#define CHROME_BROWSER_UI_JAVASCRIPT_DIALOGS_JAVASCRIPT_DIALOG_H_
+
+#include "base/memory/weak_ptr.h"
+#include "content/public/browser/javascript_dialog_manager.h"
+
+class JavaScriptDialog {
+ public:
+  virtual ~JavaScriptDialog();
+
+  static base::WeakPtr<JavaScriptDialog> Create(
+      content::WebContents* parent_web_contents,
+      content::WebContents* alerting_web_contents,
+      const base::string16& title,
+      content::JavaScriptMessageType message_type,
+      const base::string16& message_text,
+      const base::string16& default_prompt_text,
+      const content::JavaScriptDialogManager::DialogClosedCallback&
+          dialog_callback);
+
+  // Closes the dialog without sending a callback. This is useful when the
+  // JavaScriptDialogTabHelper needs to make this dialog go away so that it can
+  // respond to a call that requires it to make no callback or make a customized
+  // one.
+  virtual void CloseDialogWithoutCallback() = 0;
+};
+
+#endif  // CHROME_BROWSER_UI_JAVASCRIPT_DIALOGS_JAVASCRIPT_DIALOG_H_