Protos: Remove unused method and thus cut dependency on gwtorm

We got rid of all usages of this method and can now safely remove it.

Change-Id: Ia6a886084e2f57bc9c240a9ce317733408606566

java/com/google/gerrit/proto/BUILD

@@ -3,7 +3,6 @@ java_library(
     srcs = ["Protos.java"],
     visibility = ["//visibility:public"],
     deps = [
-        "//lib:gwtorm",
         "//lib:protobuf",
     ],
 )

java/com/google/gerrit/proto/Protos.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.proto;
 
-import com.google.gwtorm.protobuf.ProtobufCodec;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.CodedOutputStream;
 import com.google.protobuf.MessageLite;
@@ -68,29 +67,6 @@ public class Protos {
     }
   }
 
-  /**
-   * Serializes an object to a {@link ByteString} using a protobuf codec.
-   *
-   * <p>Guarantees deterministic serialization. No matter whether the use case cares about
-   * determinism or not, always use this method in preference to {@link
-   * ProtobufCodec#encodeToByteString(Object)}, which is not guaranteed deterministic.
-   *
-   * @param object the object to serialize.
-   * @param codec codec for serializing.
-   * @return a {@code ByteString} with the message contents.
-   */
-  public static <T> ByteString toByteString(T object, ProtobufCodec<T> codec) {
-    try (ByteString.Output bout = ByteString.newOutput()) {
-      CodedOutputStream cout = CodedOutputStream.newInstance(bout);
-      cout.useDeterministicSerialization();
-      codec.encode(object, cout);
-      cout.flush();
-      return bout.toByteString();
-    } catch (IOException e) {
-      throw new IllegalStateException("exception writing to ByteString", e);
-    }
-  }
-
   /**
    * Parses a byte array to a protobuf message.
    *