Replace base::str[n]casecmp with helper functions.

chrome/service/cloud_print/cloud_print_proxy_backend.cc

Index: chrome/service/cloud_print/cloud_print_proxy_backend.cc
diff --git a/chrome/service/cloud_print/cloud_print_proxy_backend.cc b/chrome/service/cloud_print/cloud_print_proxy_backend.cc
index f93215dbd66fbc7f1c7ef52bef8718b598be8929..53485ccdf161867002cc3f77e1a61cfc14598925 100644
--- a/chrome/service/cloud_print/cloud_print_proxy_backend.cc
+++ b/chrome/service/cloud_print/cloud_print_proxy_backend.cc
@@ -550,8 +550,8 @@ void CloudPrintProxyBackend::Core::OnIncomingNotification(
 
   DCHECK(base::MessageLoop::current() == backend_->core_thread_.message_loop());
   VLOG(1) << "CP_CONNECTOR: Incoming notification.";
-  if (0 == base::strcasecmp(kCloudPrintPushNotificationsSource,
-                            notification.channel.c_str()))
+  if (base::EqualsCaseInsensitiveASCII(kCloudPrintPushNotificationsSource,
+                                       notification.channel))
     HandlePrinterNotification(notification.data);
 }