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

third_party/protobuf/objectivec/GPBUnknownField.h

 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
@@ skipping 19 matching lines @@
 
 #import <Foundation/Foundation.h>
 
 @class GPBCodedOutputStream;
 @class GPBUInt32Array;
 @class GPBUInt64Array;
 @class GPBUnknownFieldSet;
 
 NS_ASSUME_NONNULL_BEGIN
 
+/// Store an unknown field. These are used in conjunction with @c GPBUnknownFieldSet
 @interface GPBUnknownField : NSObject<NSCopying>
 
+/// The field number the data is stored under.
 @property(nonatomic, readonly, assign) int32_t number;
 
-// Only one of these will be set.
+/// An array of varint values for this field.
 @property(nonatomic, readonly, strong) GPBUInt64Array *varintList;
+
+/// An array of fixed32 values for this field.
 @property(nonatomic, readonly, strong) GPBUInt32Array *fixed32List;
+
+/// An array of fixed64 values for this field.
 @property(nonatomic, readonly, strong) GPBUInt64Array *fixed64List;
-@property(nonatomic, readonly, strong) NSArray *lengthDelimitedList;  // NSData
-@property(nonatomic, readonly, strong) NSArray *groupList;  // GPBUnknownFieldSet
 
-// Only one of these should be used per Field.
+/// An array of data values for this field.
+@property(nonatomic, readonly, strong) NSArray<NSData*> *lengthDelimitedList;
+
+/// An array of groups of values for this field.
+@property(nonatomic, readonly, strong) NSArray<GPBUnknownFieldSet*> *groupList;
+
+
+/// Add a value to the varintList.
+///
+/// @param value The value to add.
 - (void)addVarint:(uint64_t)value;
+
+/// Add a value to the fixed32List.
+///
+/// @param value The value to add.
 - (void)addFixed32:(uint32_t)value;
+
+/// Add a value to the fixed64List.
+///
+/// @param value The value to add.
 - (void)addFixed64:(uint64_t)value;
+
+/// Add a value to the lengthDelimitedList.
+///
+/// @param value The value to add.
 - (void)addLengthDelimited:(NSData *)value;
+
+/// Add a value to the groupList.
+///
+/// @param value The value to add.
 - (void)addGroup:(GPBUnknownFieldSet *)value;
 
 @end
 
 NS_ASSUME_NONNULL_END