ui: Move NativeTheme files into ui/base/native_theme/ directory.

ui/base/native_theme/native_theme_base.h

Index: ui/base/native_theme/native_theme_base.h
diff --git a/ui/gfx/native_theme_base.h b/ui/base/native_theme/native_theme_base.h
similarity index 95%
rename from ui/gfx/native_theme_base.h
rename to ui/base/native_theme/native_theme_base.h
index 562f934d6af0b8139248ea28f54e8b71ff667f74..5cc86fe8fa95b56bb741cc01c87b81a3a9808636 100644
--- a/ui/gfx/native_theme_base.h
+++ b/ui/base/native_theme/native_theme_base.h
@@ -2,17 +2,21 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef UI_GFX_NATIVE_THEME_BASE_H_
-#define UI_GFX_NATIVE_THEME_BASE_H_
+#ifndef UI_BASE_NATIVE_THEME_NATIVE_THEME_BASE_H_
+#define UI_BASE_NATIVE_THEME_NATIVE_THEME_BASE_H_
+#pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "skia/ext/platform_canvas.h"
-#include "ui/gfx/native_theme.h"
+#include "ui/base/native_theme/native_theme.h"
 
 namespace gfx {
 class Rect;
 class Size;
+}
+
+namespace ui {
 
 // Theme support for non-Windows toolkits.
 class NativeThemeBase : public NativeTheme {
@@ -162,6 +166,6 @@ class NativeThemeBase : public NativeTheme {
   DISALLOW_COPY_AND_ASSIGN(NativeThemeBase);
 };
 
-}  // namespace gfx
+}  // namespace ui
 
-#endif  // UI_GFX_NATIVE_THEME_BASE_H_
+#endif  // UI_BASE_NATIVE_THEME_NATIVE_THEME_BASE_H_