exp/template/html: remove TODO comments that have been done or mooted

R=nigeltao
CC=golang-dev
https://golang.org/cl/5128041

src/pkg/exp/template/html/transition.go

@@ -9,9 +9,6 @@ import (
 	"strings"
 )
 
-// TODO: ensure transition error messages contain template name and ideally
-// line info.
-
 // transitionFunc is the array of context transition functions for text nodes.
 // A transition function takes a context and template text input, and returns
 // the updated context and the number of bytes consumed from the front of the

src/pkg/exp/template/html/url.go

@@ -21,13 +21,9 @@ func urlFilter(args ...interface{}) string {
 	if i >= 0 && strings.IndexRune(s[:i], '/') < 0 {
 		protocol := strings.ToLower(s[:i])
 		if protocol != "http" && protocol != "https" && protocol != "mailto" {
-			// Return a value that someone investigating a bug
-			// report can put into a search engine.
 			return "#" + filterFailsafe
 		}
 	}
-	// TODO: Once we handle <style>#id { background: url({{.Img}}) }</style>
-	// we will need to stop this from HTML escaping and pipeline sanitizers.
 	return s
 }