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

chrome/browser/chromeos/preferences.cc

Index: chrome/browser/chromeos/preferences.cc
diff --git a/chrome/browser/chromeos/preferences.cc b/chrome/browser/chromeos/preferences.cc
index fce3ef5874c5f93a72c35748c02a16bd8499ba37..91825655e8e976deadc52268c7e86f3f711fd073 100644
--- a/chrome/browser/chromeos/preferences.cc
+++ b/chrome/browser/chromeos/preferences.cc
@@ -233,6 +233,9 @@ void Preferences::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterIntegerPref(prefs::kLanguageRemapCapsLockKeyTo,
                              input_method::kCapsLockKey,
                              PrefService::SYNCABLE_PREF);
+  prefs->RegisterBooleanPref(prefs::kLanguageSearchKeyActsAsFunctionKey,
+                             false,
+                             PrefService::SYNCABLE_PREF);
   // We don't sync the following keyboard prefs since they are not user-
   // configurable.
   prefs->RegisterBooleanPref(prefs::kLanguageXkbAutoRepeatEnabled,
@@ -363,6 +366,8 @@ void Preferences::InitUserPrefs(PrefService* prefs) {
     mozc_integer_prefs_[i].Init(
         language_prefs::kMozcIntegerPrefs[i].pref_name, prefs, callback);
   }
+  search_key_acts_as_function_key_.Init(
+      prefs::kLanguageSearchKeyActsAsFunctionKey, prefs, callback);
   xkb_auto_repeat_enabled_.Init(
       prefs::kLanguageXkbAutoRepeatEnabled, prefs, callback);
   xkb_auto_repeat_delay_pref_.Init(