Relaunch Chrome in metro-mode with the help of a helper process.

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 3bf87a329d212d91fe7e6057a4f04ab6180ce2e3..7a2de4944d59ea4026b1177bea79826720610e5c 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1448,9 +1448,15 @@ const char kKioskModePrinting[]             = "kiosk-printing";
 #endif
 
 #if defined(OS_WIN)
+// Activates the named app; see kWaitForHandle.
+const char kActivateApp[]                   = "activate-app";
+
 // Disables profile desktop shortcuts handling, preventing their creation,
 // modification or removal.
 const char kDisableDesktopShortcuts[]       = "disable-desktop-shortcuts";
+
+// Waits for the handle to be signaled before activating.
+const char kWaitForHandle[]                 = "wait-for-handle";
 #endif
 
 #if defined(USE_AURA)