Remove the metatag transformer, which moves meta tags from body to head.

PiperOrigin-RevId: 254114976

Author: Greg Grothaus

transformer/transformer.go

@@ -43,9 +43,8 @@ var transformerFunctionMap = map[string]func(*transformers.Context) error{
 	"ampboilerplate":        transformers.AMPBoilerplate,
 	"ampruntimecss":         transformers.AMPRuntimeCSS,
 	"linktag":               transformers.LinkTag,
-	"metatag":               transformers.MetaTag,
 	"nodecleanup":           transformers.NodeCleanup,
-  "preloadimage":          transformers.PreloadImage,
+	"preloadimage":          transformers.PreloadImage,
 	"reorderhead":           transformers.ReorderHead,
 	"serversiderendering":   transformers.ServerSideRendering,
 	"stripjs":               transformers.StripJS,
@@ -61,7 +60,6 @@ var configMap = map[rpb.Request_TransformersConfig][]func(*transformers.Context)
 		// NodeCleanup should be first.
 		transformers.NodeCleanup,
 		transformers.StripJS,
-		transformers.MetaTag,
 		transformers.LinkTag,
 		transformers.AbsoluteURL,
 		transformers.AMPBoilerplate,

transformer/transformer_test.go

@@ -26,7 +26,7 @@ func TestProcess(t *testing.T) {
 		config      rpb.Request_TransformersConfig
 		expectedLen int
 	}{
-		{rpb.Request_DEFAULT, 13},
+		{rpb.Request_DEFAULT, 12},
 		{rpb.Request_NONE, 0},
 		{rpb.Request_VALIDATION, 1},
 		{rpb.Request_CUSTOM, 0},
@@ -158,7 +158,6 @@ func TestCustom(t *testing.T) {
 		"aMpBoIlerplate",
 		"AMPRuntimeCSS",
 		"linktag",
-		"metaTag",
 		"NODECLEANUP",
 		"reorderHead",
 		"serverSideRendering",