Move the web dialogs code to src/ui/web_dialogs from src/chrome

ui/web_dialogs/web_dialog_observer.h

 // Copyright (c) 2012 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_WEBUI_WEB_DIALOG_OBSERVER_H_
-#define CHROME_BROWSER_UI_WEBUI_WEB_DIALOG_OBSERVER_H_
+#ifndef UI_WEB_DIALOGS_WEB_DIALOG_OBSERVER_H_
+#define UI_WEB_DIALOGS_WEB_DIALOG_OBSERVER_H_
 #pragma once
 
+#include "ui/web_dialogs/web_dialogs_export.h"
+
 namespace content {
 class RenderViewHost;
 class WebUI;
 }
 
+namespace ui {
+
 // Implement this class to receive notifications.
-class WebDialogObserver {
+class WEB_DIALOGS_EXPORT WebDialogObserver {
  public:
   // Invoked when a web dialog has been shown.
   // |webui| is the WebUI with which the dialog is associated.
   // |render_view_host| is the RenderViewHost for the shown dialog.
   virtual void OnDialogShown(content::WebUI* webui,
                              content::RenderViewHost* render_view_host) = 0;
 
  protected:
   virtual ~WebDialogObserver() {}
 };
 
-#endif  // CHROME_BROWSER_UI_WEBUI_WEB_DIALOG_OBSERVER_H_
+}  // namespace ui
+
+#endif  // UI_WEB_DIALOGS_WEB_DIALOG_OBSERVER_H_