Revert "third_party/protobuf: Update to HEAD (83d681ee2c)"

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 c4d7d40343431157616cff87bef1cdeb08711e8e..2a42c11262694451ac0a32fb7b9fafd1ede34392 100644
--- a/third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h
+++ b/third_party/protobuf/python/google/protobuf/pyext/descriptor_pool.h
@@ -38,9 +38,9 @@
 
 namespace google {
 namespace protobuf {
-namespace python {
+class MessageFactory;
 
-struct PyMessageFactory;
+namespace python {
 
 // The (meta) type of all Messages classes.
 struct CMessageClass;
@@ -69,10 +69,20 @@ typedef struct PyDescriptorPool {
   // This pointer is owned.
   const DescriptorDatabase* database;
 
-  // The preferred MessageFactory to be used by descriptors.
-  // TODO(amauryfa): Don't create the Factory from the DescriptorPool, but
-  // use the one passed while creating message classes. And remove this member.
-  PyMessageFactory* py_message_factory;
+  // DynamicMessageFactory used to create C++ instances of messages.
+  // This object cache the descriptors that were used, so the DescriptorPool
+  // needs to get rid of it before it can delete itself.
+  //
+  // Note: A C++ MessageFactory is different from the Python MessageFactory.
+  // The C++ one creates messages, when the Python one creates classes.
+  MessageFactory* message_factory;
+
+  // Make our own mapping to retrieve Python classes from C++ descriptors.
+  //
+  // Descriptor pointers stored here are owned by the DescriptorPool above.
+  // Python references to classes are owned by this PyDescriptorPool.
+  typedef hash_map<const Descriptor*, CMessageClass*> ClassesByMessageMap;
+  ClassesByMessageMap* classes_by_descriptor;
 
   // Cache the options for any kind of descriptor.
   // Descriptor pointers are owned by the DescriptorPool above.
@@ -90,6 +100,19 @@ namespace cdescriptor_pool {
 const Descriptor* FindMessageTypeByName(PyDescriptorPool* self,
                                         const string& name);
 
+// Registers a new Python class for the given message descriptor.
+// On error, returns -1 with a Python exception set.
+int RegisterMessageClass(PyDescriptorPool* self,
+                         const Descriptor* message_descriptor,
+                         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.
+CMessageClass* GetMessageClass(PyDescriptorPool* self,
+                               const Descriptor* message_descriptor);
+
 // The functions below are also exposed as methods of the DescriptorPool type.
 
 // Looks up a message by name. Returns a PyMessageDescriptor corresponding to