Fully converted over to ICodedOutputStream for all WriteTo derivations
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
index 9119fdb..2c38333 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
@@ -177,7 +177,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       if (options_.Count > 0) {

         output.WriteArray(pbd::FieldType.Enum, 3, "options", options_);

@@ -444,7 +444,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -676,7 +676,7 @@
           }

         }

         

-        public override void WriteTo(pb::CodedOutputStream output) {

+        public override void WriteTo(pb::ICodedOutputStream output) {

           int size = SerializedSize;

           if (options_.Count > 0) {

             output.WriteArray(pbd::FieldType.Enum, 3, "options", options_);

@@ -998,7 +998,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       pb::ExtendableMessage<TestXmlMessage, TestXmlMessage.Builder>.ExtensionWriter extensionWriter = CreateExtensionWriter(this);

       if (HasChild) {

@@ -1018,7 +1018,7 @@
       }

       extensionWriter.WriteUntil(200, output);

       if (children_.Count > 0) {

-        output.WriteGroupArray(401, "children", children_);

+        output.WriteArray(pbd::FieldType.Group, 401, "children", children_);

       }

       if (textlines_.Count > 0) {

         output.WriteArray(pbd::FieldType.String, 700, "textlines", textlines_);

@@ -1487,7 +1487,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       if (HasNumber) {

         output.WriteInt32(1, "number", Number);