wm: Update namespace and header define guards.

src/platform/window_manager/real_x_connection.cc

Index: src/platform/window_manager/real_x_connection.cc
diff --git a/src/platform/window_manager/real_x_connection.cc b/src/platform/window_manager/real_x_connection.cc
index c5fac03cfc4e001f7d9a4c838eb5fc376796e21e..9e6aec0d38e8ba9096257c1de062b341fa0a3111 100644
--- a/src/platform/window_manager/real_x_connection.cc
+++ b/src/platform/window_manager/real_x_connection.cc
@@ -18,7 +18,7 @@ extern "C" {
 
 #include "window_manager/util.h"
 
-namespace chromeos {
+namespace window_manager {
 
 using std::string;
 using std::vector;
@@ -991,4 +991,4 @@ string RealXConnection::GetErrorText(int error_code) {
   return string(str);
 }
 
-}  // namespace chromeos
+}  // namespace window_manager