Remove domain from weave::Error

We don't filter out errors by domain in libweave.

BUG:26071451
Change-Id: I2114450aca1c8ede71cc45f19bd8e71d3464cb73
Reviewed-on: https://weave-review.googlesource.com/2289
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
diff --git a/src/commands/command_instance_unittest.cc b/src/commands/command_instance_unittest.cc
index 8d70b8b..803d5b4 100644
--- a/src/commands/command_instance_unittest.cc
+++ b/src/commands/command_instance_unittest.cc
@@ -143,7 +143,7 @@
   instance->SetID("testId");
 
   ErrorPtr error;
-  Error::AddTo(&error, FROM_HERE, "DOMAIN", "CODE", "MESSAGE");
+  Error::AddTo(&error, FROM_HERE, "CODE", "MESSAGE");
   instance->Abort(error.get(), nullptr);
 
   json->MergeDictionary(CreateDictionaryValue(R"({