Thrift string copy construction pathces from kevin ko

Summary: Remove unnecessary string copy constructions in C++ code

Reviewed By: mcslee

Test Plan: build


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665084 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/src/protocol/TBinaryProtocol.cpp b/lib/cpp/src/protocol/TBinaryProtocol.cpp
index 958572d..544ef88 100644
--- a/lib/cpp/src/protocol/TBinaryProtocol.cpp
+++ b/lib/cpp/src/protocol/TBinaryProtocol.cpp
@@ -10,9 +10,9 @@
 
 namespace facebook { namespace thrift { namespace protocol { 
 
-uint32_t TBinaryProtocol::writeMessageBegin(const std::string name,
-					    const TMessageType messageType,
-					    const int32_t seqid) {
+uint32_t TBinaryProtocol::writeMessageBegin(const std::string& name,
+                                            const TMessageType messageType,
+                                            const int32_t seqid) {
   return 
     writeString(name) + 
     writeByte((int8_t)messageType) +