Update //third_party/protobuf to version 3.

third_party/protobuf/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java

Index: third_party/protobuf/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java
diff --git a/third_party/protobuf/python/google/protobuf/internal/more_extensions_dynamic.proto b/third_party/protobuf/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java
similarity index 69%
copy from third_party/protobuf/python/google/protobuf/internal/more_extensions_dynamic.proto
copy to third_party/protobuf/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java
index df98ac4bd1929fda636c9e2fce1a9184ebf5d472..d535efb9b6c193c9ff89bcc9081897812899b45c 100644
--- a/third_party/protobuf/python/google/protobuf/internal/more_extensions_dynamic.proto
+++ b/third_party/protobuf/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java
@@ -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 +28,24 @@
 // (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 "google/protobuf/internal/more_extensions.proto";
-
-package google.protobuf.internal;
-
-message DynamicMessageType {
-  optional int32 a = 1;
-}
+package com.google.protobuf;
 
-extend ExtendedMessage {
-  optional int32 dynamic_int32_extension = 100;
-  optional DynamicMessageType dynamic_message_extension = 101;
+/**
+ * <p>Abstract interface for a blocking RPC channel.  {@code BlockingRpcChannel}
+ * is the blocking equivalent to {@link RpcChannel}.
+ *
+ * @author kenton@google.com Kenton Varda
+ * @author cpovirk@google.com Chris Povirk
+ */
+public interface BlockingRpcChannel {
+  /**
+   * Call the given method of the remote service and blocks until it returns.
+   * {@code callBlockingMethod()} is the blocking equivalent to
+   * {@link RpcChannel#callMethod}.
+   */
+  Message callBlockingMethod(
+      Descriptors.MethodDescriptor method,
+      RpcController controller,
+      Message request,
+      Message responsePrototype) throws ServiceException;
 }