Start consolidating non-port specific code to ui/base/dialogs.

ui/base/dialogs/base_shell_dialog.h

Index: ui/base/dialogs/base_shell_dialog.h
diff --git a/chrome/browser/ui/base_shell_dialog.h b/ui/base/dialogs/base_shell_dialog.h
similarity index 73%
rename from chrome/browser/ui/base_shell_dialog.h
rename to ui/base/dialogs/base_shell_dialog.h
index 4a5a99c1ab2056f7625cf86a56f773a56036f568..82c0cc4da15cd00bd7ff9cb93d747d562b8d3bb0 100644
--- a/chrome/browser/ui/base_shell_dialog.h
+++ b/ui/base/dialogs/base_shell_dialog.h
@@ -2,14 +2,17 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_UI_BASE_SHELL_DIALOG_H_
-#define CHROME_BROWSER_UI_BASE_SHELL_DIALOG_H_
+#ifndef UI_BASE_DIALOG_BASE_SHELL_DIALOG_H_
+#define UI_BASE_DIALOG_BASE_SHELL_DIALOG_H_
 #pragma once
 
+#include "ui/base/ui_export.h"
 #include "ui/gfx/native_widget_types.h"
 
+namespace ui {
+
 // A base class for shell dialogs.
-class BaseShellDialog {
+class UI_EXPORT BaseShellDialog {
  public:
   // Returns true if a shell dialog box is currently being shown modally
   // to the specified owner.
@@ -23,4 +26,6 @@ class BaseShellDialog {
   virtual ~BaseShellDialog() {}
 };
 
-#endif  // CHROME_BROWSER_UI_BASE_SHELL_DIALOG_H_
+}  // namespace ui
+
+#endif  // UI_BASE_DIALOG_BASE_SHELL_DIALOG_H_