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

ui/base/gtk/scoped_region.cc

+// 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.
+
+#include "ui/base/gtk/scoped_region.h"
+
+#include <gdk/gdk.h>
+
+namespace ui {
+
+ScopedRegion::ScopedRegion() : region_(NULL) {}
+
+ScopedRegion::ScopedRegion(GdkRegion* region) : region_(region) {}
+
+ScopedRegion::~ScopedRegion() {
+  Close();
+}
+
+void ScopedRegion::Set(GdkRegion* region) {
+  Close();
+  region_ = region;
+}
+
+GdkRegion* ScopedRegion::Get() {
+  return region_;
+}
+
+GdkRegion* ScopedRegion::release() {
+  GdkRegion* region = region_;
+  region_ = NULL;
+  return region;
+}
+
+void ScopedRegion::Close() {
+  if (region_) {
+    gdk_region_destroy(region_);
+    region_ = NULL;
+  }
+}
+
+}  // namespace ui