wm: Update namespace and header define guards.

src/platform/window_manager/stacking_manager.h

Index: src/platform/window_manager/stacking_manager.h
diff --git a/src/platform/window_manager/stacking_manager.h b/src/platform/window_manager/stacking_manager.h
index 7c24ed3b0c13c20209681bb9bf1971f849dfd28d..0296b7e9698fff6381ae42c33a634bdf07438038 100644
--- a/src/platform/window_manager/stacking_manager.h
+++ b/src/platform/window_manager/stacking_manager.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef __PLATFORM_WINDOW_MANAGER_STACKING_MANAGER_H__
-#define __PLATFORM_WINDOW_MANAGER_STACKING_MANAGER_H__
+#ifndef WINDOW_MANAGER_STACKING_MANAGER_H_
+#define WINDOW_MANAGER_STACKING_MANAGER_H_
 
 #include <map>
 #include <set>
@@ -19,7 +19,7 @@ extern "C" {
 
 typedef ::Window XWindow;
 
-namespace chromeos {
+namespace window_manager {
 
 class Window;
 class XConnection;
@@ -117,6 +117,6 @@ class StackingManager {
   std::set<XWindow> xids_;
 };
 
-}  // namespace chromeos
+}  // namespace window_manager
 
 #endif