Update third_party/protobuf to protobuf-v3.0.0-beta-3

third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h

Index: third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h
diff --git a/third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h b/third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h
index 16bc910c45640ea607bf1e1e5fb29c9bd1d229f1..2a42c11262694451ac0a32fb7b9fafd1ede34392 100644
--- a/third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h
+++ b/third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h
@@ -42,6 +42,9 @@ class MessageFactory;
 
 namespace python {
 
+// The (meta) type of all Messages classes.
+struct CMessageClass;
+
 // Wraps operations to the global DescriptorPool which contains information
 // about all messages and fields.
 //
@@ -78,7 +81,7 @@ typedef struct PyDescriptorPool {
   //
   // Descriptor pointers stored here are owned by the DescriptorPool above.
   // Python references to classes are owned by this PyDescriptorPool.
-  typedef hash_map<const Descriptor*, PyObject*> ClassesByMessageMap;
+  typedef hash_map<const Descriptor*, CMessageClass*> ClassesByMessageMap;
   ClassesByMessageMap* classes_by_descriptor;
 
   // Cache the options for any kind of descriptor.
@@ -101,14 +104,14 @@ const Descriptor* FindMessageTypeByName(PyDescriptorPool* self,
 // On error, returns -1 with a Python exception set.
 int RegisterMessageClass(PyDescriptorPool* self,
                          const Descriptor* message_descriptor,
-                         PyObject* message_class);
+                         CMessageClass* message_class);
 
 // Retrieves the Python class registered with the given message descriptor.
 //
 // Returns a *borrowed* reference if found, otherwise returns NULL with an
 // exception set.
-PyObject* GetMessageClass(PyDescriptorPool* self,
-                          const Descriptor* message_descriptor);
+CMessageClass* GetMessageClass(PyDescriptorPool* self,
+                               const Descriptor* message_descriptor);
 
 // The functions below are also exposed as methods of the DescriptorPool type.