Convert JsonWriter::Write to taking a const ref for the in-param

chromeos/network/network_state_handler.cc

Index: chromeos/network/network_state_handler.cc
diff --git a/chromeos/network/network_state_handler.cc b/chromeos/network/network_state_handler.cc
index a8a9ebf9addb717f3b923f9765c0f1f8e6dac52f..e7ddbcf93abcf43803ca937d8722f40183cdedd5 100644
--- a/chromeos/network/network_state_handler.cc
+++ b/chromeos/network/network_state_handler.cc
@@ -56,7 +56,7 @@ std::string GetLogName(const ManagedState* state) {
 std::string ValueAsString(const base::Value& value) {
   std::string vstr;
   base::JSONWriter::WriteWithOptions(
-      &value, base::JSONWriter::OPTIONS_OMIT_BINARY_VALUES, &vstr);
+      value, base::JSONWriter::OPTIONS_OMIT_BINARY_VALUES, &vstr);
   return vstr.empty() ? "''" : vstr;
 }