Fix the std::string error introduced in integration.
@@ -48,7 +48,7 @@ class Message;
class FieldDescriptor;
#ifdef _SHARED_PTR_H
-using shared_ptr;
+using std::shared_ptr;
#else
using internal::shared_ptr;
#endif
@@ -47,7 +47,7 @@ namespace protobuf {
class Message;
@@ -53,8 +53,8 @@ class DescriptorPool;
class MessageFactory;
-using std::std::string;
+using ::std::string;
@@ -50,7 +50,7 @@ class FieldDescriptor;
@@ -49,7 +49,7 @@ namespace protobuf {