Revert "Add POST support to XHR as well as .status and statusText support"

This reverts commit 5ef81d249b841f44c9593ffb0158d64c7e0febfc.

This appeared to make 5 XHR tests timeout.  Not sure why yet.
TBR=esprehn@chromium.org

Review URL: https://codereview.chromium.org/808663002

engine/src/flutter/tools/skygo/sky_server.go

@@ -6,7 +6,6 @@ package main
 
 import (
     "flag"
-    "io/ioutil"
     "net/http"
     "path"
     "strings"
@@ -39,11 +38,6 @@ func main() {
     genRoot := path.Join(root, "out", *configuration, "gen")
 
     http.Handle("/", skyHandler(root))
-    http.HandleFunc("/echo_post", func(w http.ResponseWriter, r *http.Request) {
-        defer r.Body.Close()
-        body, _ := ioutil.ReadAll(r.Body)
-        w.Write(body)
-    })
     http.Handle("/mojo/public/", http.StripPrefix("/mojo/public/", skyHandler(path.Join(genRoot, "mojo", "public"))))
     http.Handle("/mojo/services/", http.StripPrefix("/mojo/services/", skyHandler(path.Join(genRoot, "mojo", "services"))))
     http.Handle("/sky/services/", http.StripPrefix("/sky/services/", skyHandler(path.Join(genRoot, "sky", "services"))))

engine/src/flutter/tools/skygo/sky_server.sha1

@@ -1 +1 @@
-f6b808791e8ab0290cb18bc8b444159074c395ae
+7b6d0d60949ad71a35a88430b2eb7d70fe7334b6