Move XMLHttpRequest#responseText to a getter

sky/framework/xmlhttprequest.sky

Index: sky/framework/xmlhttprequest.sky
diff --git a/sky/framework/xmlhttprequest.sky b/sky/framework/xmlhttprequest.sky
index 7018d084f2096e132d87cb441c94df0b7bc8089b..5b1090ad9fa1b89256656fba5cbbc30e941cd218 100644
--- a/sky/framework/xmlhttprequest.sky
+++ b/sky/framework/xmlhttprequest.sky
@@ -16,13 +16,13 @@ class Private {
     this.request = null;
     this.loader = null;
     this.headers = new Map();
+    this.responseText = null;

[esprehn, 2014/11/21 08:08:28]

default is empty string not null in the real one.

   }
 }
 
 class XMLHttpRequest {
   constructor() {
     this[kPrivate] = new Private;
-    this.responseText = null;
   }
 
   onload() {
@@ -31,6 +31,10 @@ class XMLHttpRequest {
   onerror(error) {
   }
 
+  get responseText() {
+    return this[kPrivate].responseText;
+  }
+
   open(method, url) {
     var request = new loader.URLRequest();
     request.url = new URL(url, document.URL);
@@ -64,7 +68,7 @@ class XMLHttpRequest {
     priv.loader.start(priv.request).then(function(result) {
       return core.drainData(result.response.body).then(function(result) {
         outstandingRequests.delete(self);
-        self.responseText = unicode.decodeUtf8String(new Uint8Array(result.buffer));
+        priv.responseText = unicode.decodeUtf8String(new Uint8Array(result.buffer));
         self.onload();
       });
     }).catch(function(error) {