chromium_build_stats: fix trace viewer

appengine/chromium_build_stats/gopath/src/ninjalog/traceviewer/traceviewer.go

 // Copyright 2014 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 traceviewer generates trace-viewer page from *ninjalog.NinjaLog.
 
 */
 package traceviewer
 
@@ skipping 58 matching lines @@
 
         f, err := os.Open(t.fname)
         if err != nil {
                 return nil, err
         }
         defer f.Close()
         var w bytes.Buffer
         scanner := bufio.NewScanner(f)
         for scanner.Scan() {
                 line := scanner.Text()
-                if line == `<script id="viewer-data" type="application/json">` {
+                if line == `<script id="viewer-data" type="text/plain">` {
                         fmt.Fprintf(&w, "%s\n", line)
                         break
                 }
                 if strings.HasPrefix(line, `  <title>Trace from`) {
                         fmt.Fprintf(&w, "  <title>Trace from %s</title>\n", template.HTMLEscapeString(fname))
                         continue
                 }
                 fmt.Fprintf(&w, "%s\n", line)
         }
         fmt.Fprintf(&w, "%s\n", buf.String())
         for scanner.Scan() {
                 line := scanner.Text()
                 if line == `</script>` {
                         fmt.Fprintf(&w, "%s\n", line)
                         break
                 }
         }
         for scanner.Scan() {
                 fmt.Fprintf(&w, "%s\n", scanner.Text())
         }
         if err = scanner.Err(); err != nil {
                 return nil, err
         }
         return w.Bytes(), err
 }