PART2: Make SignedSettings use proper Value types instead of string all around the place.

chrome/browser/ui/webui/options/chromeos/system_settings_provider.cc

Index: chrome/browser/ui/webui/options/chromeos/system_settings_provider.cc
diff --git a/chrome/browser/ui/webui/options/chromeos/system_settings_provider.cc b/chrome/browser/ui/webui/options/chromeos/system_settings_provider.cc
index 359a1930e08cb177cff2eae2c37d2be98607a5c5..1d629565bcd9c363e1abaae63136d8c45603fad3 100644
--- a/chrome/browser/ui/webui/options/chromeos/system_settings_provider.cc
+++ b/chrome/browser/ui/webui/options/chromeos/system_settings_provider.cc
@@ -197,15 +197,15 @@ SystemSettingsProvider::~SystemSettingsProvider() {
   STLDeleteElements(&timezones_);
 }
 
-void SystemSettingsProvider::DoSet(const std::string& path, Value* in_value) {
+void SystemSettingsProvider::DoSet(const std::string& path,
+                                   const base::Value& in_value) {
   // Non-guest users can change the time zone.
   if (UserManager::Get()->IsLoggedInAsGuest())
     return;
 
   if (path == kSystemTimezone) {
     string16 value;
-    if (!in_value || !in_value->IsType(Value::TYPE_STRING) ||
-        !in_value->GetAsString(&value))
+    if (!in_value.IsType(Value::TYPE_STRING) || !in_value.GetAsString(&value))
       return;
     const icu::TimeZone* timezone = GetTimezone(value);
     if (!timezone)