Add the partial screen magnifier to Chrome OS.

chrome/browser/chromeos/login/wizard_controller.cc

Index: chrome/browser/chromeos/login/wizard_controller.cc
diff --git a/chrome/browser/chromeos/login/wizard_controller.cc b/chrome/browser/chromeos/login/wizard_controller.cc
index 49430286b027dce450d69d743a2298e08e942495..f6534bea5b604ebf2fb2270c6d974b578df45f71 100644
--- a/chrome/browser/chromeos/login/wizard_controller.cc
+++ b/chrome/browser/chromeos/login/wizard_controller.cc
@@ -410,10 +410,10 @@ void WizardController::RegisterPrefs(PrefService* local_state) {
                                      false,
                                      PrefService::UNSYNCABLE_PREF);
   }
-  if (local_state->FindPreference(prefs::kScreenMagnifierEnabled) == NULL) {
-    local_state->RegisterBooleanPref(prefs::kScreenMagnifierEnabled,
-                                     false,
-                                     PrefService::UNSYNCABLE_PREF);
+  if (local_state->FindPreference(prefs::kScreenMagnifierType) == NULL) {
+    local_state->RegisterStringPref(prefs::kScreenMagnifierType,
+                                    "",
+                                    PrefService::UNSYNCABLE_PREF);
   }
   if (local_state->FindPreference(prefs::kVirtualKeyboardEnabled) == NULL) {
     local_state->RegisterBooleanPref(prefs::kVirtualKeyboardEnabled,