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

third_party/protobuf/objectivec/GPBRuntimeTypes.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 49 matching lines @@
   float valueFloat;
   double valueDouble;
   GPB_UNSAFE_UNRETAINED NSData *valueData;
   GPB_UNSAFE_UNRETAINED NSString *valueString;
   GPB_UNSAFE_UNRETAINED GPBMessage *valueMessage;
   int32_t valueEnum;
 } GPBGenericValue;
 
 // Do not change the order of this enum (or add things to it) without thinking
 // about it very carefully. There are several things that depend on the order.
-typedef enum {
+typedef NS_ENUM(uint8_t, GPBDataType) {
   GPBDataTypeBool = 0,
   GPBDataTypeFixed32,
   GPBDataTypeSFixed32,
   GPBDataTypeFloat,
   GPBDataTypeFixed64,
   GPBDataTypeSFixed64,
   GPBDataTypeDouble,
   GPBDataTypeInt32,
   GPBDataTypeInt64,
   GPBDataTypeSInt32,
   GPBDataTypeSInt64,
   GPBDataTypeUInt32,
   GPBDataTypeUInt64,
   GPBDataTypeBytes,
   GPBDataTypeString,
   GPBDataTypeMessage,
   GPBDataTypeGroup,
   GPBDataTypeEnum,
-} GPBDataType;
+};
 
 enum {
   // A count of the number of types in GPBDataType. Separated out from the
   // GPBDataType enum to avoid warnings regarding not handling
   // GPBDataType_Count in switch statements.
   GPBDataType_Count = GPBDataTypeEnum + 1
 };
 
 // An extension range.
 typedef struct GPBExtensionRange {
   uint32_t start;  // inclusive
   uint32_t end;    // exclusive
 } GPBExtensionRange;