Add preparers for xml

Bug: 181070625
Test: m nothing
Change-Id: I150889a025e1c23eebe1e2764b07fdbd2babef49

xml/Android.bp

@@ -13,6 +13,7 @@ bootstrap_go_package {
         "soong-etc",
     ],
     srcs: [
+        "testing.go",
         "xml.go",
     ],
     testSrcs: [

xml/testing.go

@@ -0,0 +1,19 @@
+// Copyright 2018 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package xml
+
+import "android/soong/android"
+
+var PreparerForTestWithXmlBuildComponents = android.FixtureRegisterWithContext(registerXmlBuildComponents)

xml/xml.go

@@ -53,10 +53,14 @@ var (
 )
 
 func init() {
-	android.RegisterModuleType("prebuilt_etc_xml", PrebuiltEtcXmlFactory)
+	registerXmlBuildComponents(android.InitRegistrationContext)
 	pctx.HostBinToolVariable("XmlLintCmd", "xmllint")
 }
 
+func registerXmlBuildComponents(ctx android.RegistrationContext) {
+	ctx.RegisterModuleType("prebuilt_etc_xml", PrebuiltEtcXmlFactory)
+}
+
 type prebuiltEtcXmlProperties struct {
 	// Optional DTD that will be used to validate the xml file.
 	Schema *string `android:"path"`