Update //third_party/protobuf to version 3.

third_party/protobuf/objectivec/GPBExtensionInternals.h

Index: third_party/protobuf/objectivec/GPBExtensionInternals.h
diff --git a/third_party/protobuf/python/google/protobuf/internal/more_extensions_dynamic.proto b/third_party/protobuf/objectivec/GPBExtensionInternals.h
similarity index 65%
copy from third_party/protobuf/python/google/protobuf/internal/more_extensions_dynamic.proto
copy to third_party/protobuf/objectivec/GPBExtensionInternals.h
index df98ac4bd1929fda636c9e2fce1a9184ebf5d472..2b980aefa4c45e51ec06ac1287e197f6290a9484 100644
--- a/third_party/protobuf/python/google/protobuf/internal/more_extensions_dynamic.proto
+++ b/third_party/protobuf/objectivec/GPBExtensionInternals.h
@@ -1,6 +1,6 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
+// 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
@@ -28,22 +28,23 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Author: jasonh@google.com (Jason Hsueh)
-//
-// This file is used to test a corner case in the CPP implementation where the
-// generated C++ type is available for the extendee, but the extension is
-// defined in a file whose C++ type is not in the binary.
+#import <Foundation/Foundation.h>
 
+#import "GPBDescriptor.h"
 
-import "google/protobuf/internal/more_extensions.proto";
+@class GPBCodedInputStream;
+@class GPBCodedOutputStream;
+@class GPBExtensionRegistry;
 
-package google.protobuf.internal;
+void GPBExtensionMergeFromInputStream(GPBExtensionDescriptor *extension,
+                                      BOOL isPackedOnStream,
+                                      GPBCodedInputStream *input,
+                                      GPBExtensionRegistry *extensionRegistry,
+                                      GPBMessage *message);
 
-message DynamicMessageType {
-  optional int32 a = 1;
-}
+size_t GPBComputeExtensionSerializedSizeIncludingTag(
+    GPBExtensionDescriptor *extension, id value);
 
-extend ExtendedMessage {
-  optional int32 dynamic_int32_extension = 100;
-  optional DynamicMessageType dynamic_message_extension = 101;
-}
+void GPBWriteExtensionValueToOutputStream(GPBExtensionDescriptor *extension,
+                                          id value,
+                                          GPBCodedOutputStream *output);