X11: Better timestamp handling for _NET_ACTIVE_WINDOW

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 09ba0d3d697b19306ac5589348b7262e7011e20a..6a98f11440cf5f9abfff3031025ce22ebade8cb2 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1133,6 +1133,9 @@ const char kHelpShort[]                     = "h";
 
 // Specifies which password store to use (detect, default, gnome, kwallet).
 const char kPasswordStore[]                 = "password-store";
+
+// Updates X11Desktophandler::wm_user_time_ms with the latest X server time.
+const char kWmUserTimeMs[]              = "wm-user-time-ms";
 #endif
 
 #if defined(OS_MACOSX)