gtk: Move ScopedRegion into scoped_region.{h,cc}.

ui/base/gtk/scoped_handle_gtk.h

-// Copyright (c) 2011 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 UI_BASE_GTK_SCOPED_HANDLE_GTK_H_
-#define UI_BASE_GTK_SCOPED_HANDLE_GTK_H_
-#pragma once
-
-#include <gdk/gdk.h>
-
-namespace ui {
-
-// Wraps a GdkRegion. This class provides the same methods as ScopedGDIObject in
-// scoped_handle_win.
-class ScopedRegion {
- public:
-  ScopedRegion() : region_(NULL) {}
-  explicit ScopedRegion(GdkRegion* region) : region_(region) {}
-
-  ~ScopedRegion() {
-    Close();
-  }
-
-  void Set(GdkRegion* region) {
-    Close();
-
-    region_ = region;
-  }
-
-  GdkRegion* Get() {
-    return region_;
-  }
-
-  GdkRegion* release() {
-    GdkRegion* region = region_;
-    region_ = NULL;
-    return region;
-  }
-
- private:
-  void Close() {
-    if (region_) {
-      gdk_region_destroy(region_);
-      region_ = NULL;
-    }
-  }
-
-  GdkRegion* region_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedRegion);
-};
-
-}  // namespace ui
-
-#endif  // UI_BASE_GTK_SCOPED_HANDLE_GTK_H_