Canged CodedInputStream.ReadTag to use boolean result with out params to
support reading a field name rather than a field tag.
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs
index 375f5c3..4316350 100644
--- a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs
@@ -196,11 +196,12 @@
       }

       

       public override Builder MergeFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {

-        while (true) {

-          uint tag = input.ReadTag();

+        uint tag;

+        string field_name;

+        while (input.ReadTag(out tag, out field_name)) {

           switch (tag) {

             case 0: {

-              return this;

+              throw InvalidProtocolBufferException.InvalidTag();

             }

             default: {

               if (pb::WireFormat.IsEndGroupTag(tag)) {

@@ -220,6 +221,8 @@
             }

           }

         }

+        

+        return this;

       }