Remove legacy StartsWithASCII function.

chromeos/settings/cros_settings_provider.cc

Index: chromeos/settings/cros_settings_provider.cc
diff --git a/chromeos/settings/cros_settings_provider.cc b/chromeos/settings/cros_settings_provider.cc
index dceed62f9e783613057bd2a6c4f1a95966e6ec99..d6e901445fc6f4feb431a4027466f071bf59d0e6 100644
--- a/chromeos/settings/cros_settings_provider.cc
+++ b/chromeos/settings/cros_settings_provider.cc
@@ -27,7 +27,7 @@ void CrosSettingsProvider::Set(const std::string& path,
   // It should not reach here from UI in the guest mode, but just in case.
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kGuestSession) &&
-      !::base::StartsWithASCII(path, "cros.session.", true)) {
+      !base::StartsWith(path, "cros.session.", base::CompareCase::SENSITIVE)) {
     LOG(ERROR) << "Ignoring the guest request to change: " << path;
     return;
   }