Made return types of various Value::DeepCopy() implementations more specific

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 61c824eaecd8d164934166fe7e9ab49991f98e69..816a183d2545d741dbda2682e009c5d36a494bc2 100644
--- a/chrome/service/cloud_print/cloud_print_proxy_backend.cc
+++ b/chrome/service/cloud_print/cloud_print_proxy_backend.cc
@@ -269,8 +269,7 @@ CloudPrintProxyBackend::Core::Core(CloudPrintProxyBackend* backend,
       job_poll_scheduled_(false) {
   if (print_system_settings) {
     // It is possible to have no print settings specified.
-    print_system_settings_.reset(
-        reinterpret_cast<DictionaryValue*>(print_system_settings->DeepCopy()));
+    print_system_settings_.reset(print_system_settings->DeepCopy());
   }
 }