Added support for multiple parameters to Extension API callbacks.

chrome/browser/chromeos/extensions/echo_private_api.cc

Index: chrome/browser/chromeos/extensions/echo_private_api.cc
diff --git a/chrome/browser/chromeos/extensions/echo_private_api.cc b/chrome/browser/chromeos/extensions/echo_private_api.cc
index a48c704b25e081ae092f24c6993930717c43c6ad..9c1729d371ba7dac1d5711cc7ff66198da227ad3 100644
--- a/chrome/browser/chromeos/extensions/echo_private_api.cc
+++ b/chrome/browser/chromeos/extensions/echo_private_api.cc
@@ -44,6 +44,6 @@ GetRegistrationCodeFunction::~GetRegistrationCodeFunction() {
 bool GetRegistrationCodeFunction::RunImpl() {
   std::string type;
   EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &type));
-  result_.reset(GetValueForRegistrationCodeType(type));
+  SetResult(GetValueForRegistrationCodeType(type));
   return true;
 }