Add power-user keyboard mode for ChromeOS with Search key acting as a typical Fn key.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 55bf1c9f378ea444d4d8bf7d59a60b634a4d6067..550037305ab5ab97cca93640c7d3572c877efb3d 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -713,6 +713,11 @@ const char kLanguageRemapAltKeyTo[] =
 const char kLanguageRemapCapsLockKeyTo[] =
     "settings.language.remap_caps_lock_key_to";
 
+// A boolean pref which determines whether the Search key should act like a
+// Function key when held down.
+const char kLanguageSearchKeyActsAsFunctionKey[] =
+    "settings.language.search_key_acts_as_function_key";
+
 // A boolean pref which determines whether key repeat is enabled.
 const char kLanguageXkbAutoRepeatEnabled[] =
     "settings.language.xkb_auto_repeat_enabled_r2";