Create ash memory monitor

ash/ash_switches.h

Index: ash/ash_switches.h
diff --git a/ash/ash_switches.h b/ash/ash_switches.h
index 5ed521f126f9baf5d845adab57e61ae94b9afa7f..6da4d7bd431fa28635d636cc726a80c7c90feac9 100644
--- a/ash/ash_switches.h
+++ b/ash/ash_switches.h
@@ -7,6 +7,8 @@
 
 #include "ash/ash_export.h"
 
+#include "build/build_config.h"
+
 namespace ash {
 namespace switches {
 
@@ -24,6 +26,9 @@ ASH_EXPORT extern const char kAshDisableAutoWindowPlacement[];
 ASH_EXPORT extern const char kAshDisablePanelFitting[];
 ASH_EXPORT extern const char kAshDisableBootAnimation2[];
 ASH_EXPORT extern const char kAshEnableAdvancedGestures[];
+#if defined(OS_LINUX)
+ASH_EXPORT extern const char kAshEnableMemoryMonitor[];
+#endif
 ASH_EXPORT extern const char kAshEnableOak[];
 ASH_EXPORT extern const char kAshEnableTrayDragging[];
 ASH_EXPORT extern const char kAshLauncherPerDisplay[];