[New go generator] Implement declaring unions.

mojom/generators/go/templates/templates.go

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package templates
 
 import (
         "bytes"
         "text/template"
 
@@ skipping 16 matching lines @@
 
         if err != nil {
                 panic(err)
         }
         return src
 }
 
 func init() {
         // We parse the subtemplates only once.
         goFileTmpl = template.New("GoFileTemplate")
+
         template.Must(goFileTmpl.Parse(goFileTemplate))
         template.Must(goFileTmpl.Parse(nonNullableFieldDecodingTmplText))
         template.Must(goFileTmpl.Parse(fieldDecodingTmplText))
 
         template.Must(goFileTmpl.Parse(nonNullableFieldEncodingTmplText))
         template.Must(goFileTmpl.Parse(fieldEncodingTmplText))
         template.Must(goFileTmpl.Parse(structEncodingTmplText))
         template.Must(goFileTmpl.Parse(structDeclTmplText))
         template.Must(goFileTmpl.Parse(structVersions))
         template.Must(goFileTmpl.Parse(structDecodingTmplText))
+
+        template.Must(goFileTmpl.Parse(unionDeclTmplText))
+        template.Must(goFileTmpl.Parse(unionInterfaceDeclTmplText))
+        template.Must(goFileTmpl.Parse(unionFieldDeclTmplText))
+        template.Must(goFileTmpl.Parse(unknownUnionFieldDeclTmplText))
 }
 
 const goFileTemplate = `
 {{- define "FileTemplate" -}}
 {{- $fileTmpl := . -}}
 package {{$fileTmpl.PackageName}}
 
 import (
         {{range $import := $fileTmpl.Imports}}
         {{$import.PackageName}} "{{$import.PackagePath}}"
         {{end}}
 )
 
 {{- range $struct := $fileTmpl.Structs}}
         {{ template "StructDecl" $struct }}
 
         {{ template "StructEncodingTmpl" $struct }}
 
         {{ template "StructVersions" $struct }}
 
         {{ template "StructDecodingTmpl" $struct }}
 {{- end}}
+
+{{- range $union := $fileTmpl.Imports}}

[vardhan, 2016/06/08 20:45:47]

hm.. did you mean $fileTmpl.Unions?

and below this line, did you mean $union instead of $struct?

[azani, 2016/06/08 23:51:48]

Done.

+        {{ template "UnionDecl" $struct }}
+{{- end}}
 {{- end -}}
 `