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 cdc5d44f3574347a679224c4519009d2685b4bc1..a78e211647c8dda631612725f5f5dca58b520efb 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";