third_party/protobuf: update to upstream r371

third_party/protobuf/src/google/protobuf/extension_set.h

Index: third_party/protobuf/src/google/protobuf/extension_set.h
diff --git a/third_party/protobuf/src/google/protobuf/extension_set.h b/third_party/protobuf/src/google/protobuf/extension_set.h
index 1ca9de75b414c6697ee811ab62e62bdc3f5b03b4..68ce423d9bd61cfce7afe60e7ef4e0d47f3d196b 100644
--- a/third_party/protobuf/src/google/protobuf/extension_set.h
+++ b/third_party/protobuf/src/google/protobuf/extension_set.h
@@ -39,11 +39,11 @@
 #define GOOGLE_PROTOBUF_EXTENSION_SET_H__
 
 #include <vector>
-#include <stack>
 #include <map>
 #include <utility>
 #include <string>
 
+
 #include <google/protobuf/stubs/common.h>
 
 namespace google {
@@ -214,6 +214,7 @@ class LIBPROTOBUF_EXPORT ExtensionSet {
 
   bool Has(int number) const;
   int ExtensionSize(int number) const;   // Size of a repeated extension.
+  FieldType ExtensionType(int number) const;
   void ClearExtension(int number);
 
   // singular fields -------------------------------------------------
@@ -453,6 +454,7 @@ class LIBPROTOBUF_EXPORT ExtensionSet {
     int SpaceUsedExcludingSelf() const;
   };
 
+
   // Gets the extension with the given number, creating it if it does not
   // already exist.  Returns true if the extension did not already exist.
   bool MaybeNewExtension(int number, const FieldDescriptor* descriptor,