Temporarily re-introduce load-component-extension switch.

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 93b35fb56f1eb516d2b245900a703d96b6d3700d..3a73a22ea0df02234ba6277dc4f21a6837a8e8e6 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -552,6 +552,9 @@ const char kKioskMode[]                     = "kiosk";
 // See http://crbug.com/31395.
 const char kKioskModePrinting[]             = "kiosk-printing";
 
+// Comma-separated list of directories with component extensions to load.
+const char kLoadComponentExtension[]        = "load-component-extension";
+
 // Loads an extension from the specified directory.
 const char kLoadExtension[]                 = "load-extension";