components: Create web_modal component.

chrome/browser/ui/web_contents_modal_dialog_host.h

-// Copyright (c) 2013 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_WEB_CONTENTS_MODAL_DIALOG_HOST_H_
-#define CHROME_BROWSER_UI_WEB_CONTENTS_MODAL_DIALOG_HOST_H_
-
-#include "ui/gfx/point.h"
-#include "ui/gfx/size.h"
-
-// Observer to be implemented to update web contents modal dialogs when the host
-// indicates their position needs to be changed.
-class WebContentsModalDialogHostObserver {
- public:
-  virtual ~WebContentsModalDialogHostObserver();
-
-  virtual void OnPositionRequiresUpdate() = 0;
-
- protected:
-  WebContentsModalDialogHostObserver();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(WebContentsModalDialogHostObserver);
-};
-
-// Interface for supporting positioning of web contents modal dialogs over a
-// window/widget.
-class WebContentsModalDialogHost {
- public:
-  virtual ~WebContentsModalDialogHost();
-
-  virtual gfx::Point GetDialogPosition(const gfx::Size& size) = 0;
-
-  // Add/remove observer.
-  virtual void AddObserver(WebContentsModalDialogHostObserver* observer) = 0;
-  virtual void RemoveObserver(WebContentsModalDialogHostObserver* observer) = 0;
-
- protected:
-  WebContentsModalDialogHost();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(WebContentsModalDialogHost);
-};
-
-#endif  // CHROME_BROWSER_UI_WEB_CONTENTS_MODAL_DIALOG_HOST_H_