third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/src/google/protobuf/arena.h

Index: third_party/protobuf/src/google/protobuf/arena.h
diff --git a/third_party/protobuf/src/google/protobuf/arena.h b/third_party/protobuf/src/google/protobuf/arena.h
index cf07b9fc97c0cf4b7f7f4dba9caa5a9edc963833..870665076fb8929968719201da61431a0e7d903d 100644
--- a/third_party/protobuf/src/google/protobuf/arena.h
+++ b/third_party/protobuf/src/google/protobuf/arena.h
@@ -28,6 +28,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// This file defines an Arena allocator for better allocation performance.
+
 #ifndef GOOGLE_PROTOBUF_ARENA_H__
 #define GOOGLE_PROTOBUF_ARENA_H__
 
@@ -77,8 +79,13 @@ template<typename T> void arena_destruct_object(void* object) {
 template<typename T> void arena_delete_object(void* object) {
   delete reinterpret_cast<T*>(object);
 }
-inline void arena_free(void* object, size_t /* size */) {
-  free(object);
+inline void arena_free(void* object, size_t size) {
+#if defined(__GXX_DELETE_WITH_SIZE__) || defined(__cpp_sized_deallocation)
+  ::operator delete(object, size);
+#else
+  (void)size;
+  ::operator delete(object);
+#endif
 }
 
 }  // namespace internal
@@ -142,7 +149,7 @@ struct ArenaOptions {
         max_block_size(kDefaultMaxBlockSize),
         initial_block(NULL),
         initial_block_size(0),
-        block_alloc(&malloc),
+        block_alloc(&::operator new),
         block_dealloc(&internal::arena_free),
         on_arena_init(NULL),
         on_arena_reset(NULL),
@@ -211,12 +218,10 @@ struct ArenaOptions {
 //
 // This protocol is implemented by all arena-enabled proto2 message classes as
 // well as RepeatedPtrField.
-
-#if __cplusplus >= 201103L
-class LIBPROTOBUF_EXPORT Arena final {
-#else
+//
+// Do NOT subclass Arena. This class will be marked as final when C++11 is
+// enabled.
 class LIBPROTOBUF_EXPORT Arena {
-#endif
  public:
   // Arena constructor taking custom options. See ArenaOptions below for
   // descriptions of the options available.
@@ -454,7 +459,7 @@ class LIBPROTOBUF_EXPORT Arena {
 
   // Combines SpaceAllocated and SpaceUsed. Returns a pair of
   // <space_allocated, space_used>.
-  GOOGLE_ATTRIBUTE_NOINLINE pair<uint64, uint64> SpaceAllocatedAndUsed() const;
+  GOOGLE_ATTRIBUTE_NOINLINE std::pair<uint64, uint64> SpaceAllocatedAndUsed() const;
 
   // Frees all storage allocated by this arena after calling destructors
   // registered with OwnDestructor() and freeing objects registered with Own().
@@ -608,6 +613,7 @@ class LIBPROTOBUF_EXPORT Arena {
                    const T>(static_cast<const T*>(0))) == sizeof(char) ||
                 google::protobuf::internal::has_trivial_destructor<T>::value> {};
 
+ private:
   // CreateMessage<T> requires that T supports arenas, but this private method
   // works whether or not T supports arenas. These are not exposed to user code
   // as it can cause confusing API usages, and end up having double free in
@@ -801,7 +807,7 @@ class LIBPROTOBUF_EXPORT Arena {
   template <typename T>
   static void CreateInArenaStorageInternal(
       T* ptr, Arena* arena, google::protobuf::internal::false_type) {
-    new (ptr) T;
+    new (ptr) T();
   }
 
   template <typename T>