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

third_party/protobuf/objectivec/GPBUnknownField.h

Index: third_party/protobuf/objectivec/GPBUnknownField.h
diff --git a/third_party/protobuf/objectivec/GPBUnknownField.h b/third_party/protobuf/objectivec/GPBUnknownField.h
index 12d72a9acd5cc0b2de0b9d99c430c5363a872a5b..0f301e47839ef4890c6816ac722f40ded91fdcff 100644
--- a/third_party/protobuf/objectivec/GPBUnknownField.h
+++ b/third_party/protobuf/objectivec/GPBUnknownField.h
@@ -37,22 +37,51 @@
 
 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