Update //third_party/protobuf to version 3.

third_party/protobuf/objectivec/GPBBootstrap.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.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Objective C runtime has complete enough info that most protos don’t end
+// up using this, so leaving it on is no cost or very little cost.  If you
+// happen to see it causing bloat, this is the way to disable it. If you do
+// need to disable it, try only disabling it for Release builds as having
+// full TextFormat can be useful for debugging.
+#ifndef GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS
+#define GPBOBJC_SKIP_MESSAGE_TEXTFORMAT_EXTRAS 0
+#endif
+
+// Most uses of protocol buffers don't need field options, by default the
+// static data will be compiled out, define this to 1 to include it. The only
+// time you need this is if you are doing introspection of the protocol buffers.
+#ifndef GPBOBJC_INCLUDE_FIELD_OPTIONS
+#define GPBOBJC_INCLUDE_FIELD_OPTIONS 0
+#endif
+
+// Used in the generated code to give sizes to enums. int32_t was chosen based
+// on the fact that Protocol Buffers enums are limited to this range.
+#if !__has_feature(objc_fixed_enum)
+ #error All supported Xcode versions should support objc_fixed_enum.
+#endif
+// If the headers are imported into Objective-C++, we can run into an issue
+// where the defintion of NS_ENUM (really CF_ENUM) changes based on the C++
+// standard that is in effect.  If it isn't C++11 or higher, the definition
+// doesn't allow us to forward declare. We work around this one case by
+// providing a local definition. The default case has to use NS_ENUM for the
+// magic that is Swift bridging of enums.
+#if (__cplusplus && __cplusplus < 201103L)
+ #define GPB_ENUM(X) enum X : int32_t X; enum X : int32_t
+#else
+ #define GPB_ENUM(X) NS_ENUM(int32_t, X)
+#endif
+// GPB_ENUM_FWD_DECLARE is used for forward declaring enums, ex:
+//   GPB_ENUM_FWD_DECLARE(Foo_Enum)
+//   @property (nonatomic) Foo_Enum value;
+#define GPB_ENUM_FWD_DECLARE(X) enum X : int32_t
+
+// Based upon CF_INLINE. Forces inlining in release.
+#if !defined(DEBUG)
+#define GPB_INLINE static __inline__ __attribute__((always_inline))
+#else
+#define GPB_INLINE static __inline__
+#endif
+
+// For use in public headers that might need to deal with ARC.
+#ifndef GPB_UNSAFE_UNRETAINED
+#if __has_feature(objc_arc)
+#define GPB_UNSAFE_UNRETAINED __unsafe_unretained
+#else
+#define GPB_UNSAFE_UNRETAINED
+#endif
+#endif
+
+// If property name starts with init we need to annotate it to get past ARC.
+// http://stackoverflow.com/questions/18723226/how-do-i-annotate-an-objective-c-property-with-an-objc-method-family/18723227#18723227
+#define GPB_METHOD_FAMILY_NONE __attribute__((objc_method_family(none)))
+
+// The protoc-gen-objc version which works with the current version of the
+// generated Objective C sources.  In general we don't want to change the
+// runtime interfaces (or this version) as it means everything has to be
+// regenerated.
+#define GOOGLE_PROTOBUF_OBJC_GEN_VERSION 30000