Add a Cocoa version of the auto-dismissing dialog.

chrome/browser/ui/javascript_dialogs/javascript_dialog_cocoa.h

Index: chrome/browser/ui/javascript_dialogs/javascript_dialog_cocoa.h
diff --git a/chrome/browser/ui/javascript_dialogs/javascript_dialog_cocoa.h b/chrome/browser/ui/javascript_dialogs/javascript_dialog_cocoa.h
new file mode 100644
index 0000000000000000000000000000000000000000..5b6b5b4f6fa9bc5b45855c4b4eebb7ba02e7927b
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+++ b/chrome/browser/ui/javascript_dialogs/javascript_dialog_cocoa.h
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+// 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_COCOA_H_
+#define CHROME_BROWSER_UI_JAVASCRIPT_DIALOGS_JAVASCRIPT_DIALOG_COCOA_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "chrome/browser/ui/javascript_dialogs/javascript_dialog.h"
+#include "content/public/browser/javascript_dialog_manager.h"
+
+// A Cocoa version of a JavaScript dialog that automatically dismisses itself
+// when the user switches away to a different tab, used for WebContentses that
+// are browser tabs.
+class JavaScriptDialogCocoa : public JavaScriptDialog {
+ public:
+  class JavaScriptDialogCocoaImpl;
+
+  ~JavaScriptDialogCocoa() override;
+
+  static base::WeakPtr<JavaScriptDialogCocoa> 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);
+
+  // JavaScriptDialog:
+  void CloseDialogWithoutCallback() override;
+
+ private:
+  JavaScriptDialogCocoa(
+      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);
+
+  std::unique_ptr<JavaScriptDialogCocoaImpl> impl_;
+
+  base::WeakPtrFactory<JavaScriptDialogCocoa> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(JavaScriptDialogCocoa);
+};
+
+#endif  // CHROME_BROWSER_UI_JAVASCRIPT_DIALOGS_JAVASCRIPT_DIALOG_COCOA_H_