Fixed the cross-frame security error

Author: Ke, Mingze

chrome-extension/manifest.json

@@ -10,7 +10,8 @@
     "js": [
       "contentScript.js"
     ],
-    "run_at": "document_start"
+    "run_at": "document_start",
+    "all_frames": true
   }],
   "icons": {
     "128": "assets/icon_128.png"

lib/chrome._api.js

@@ -5,7 +5,6 @@ chrome._api = (function (window) {
   'use strict';
 
   var slice = Array.prototype.slice,
-    wnd = window.top,
     undef = undefined,
     callbackHash = {},
     listenerHash = {},
@@ -47,15 +46,15 @@ chrome._api = (function (window) {
   }
 
   function invoke(id, method, params) {
-    wnd.postMessage({
+    window.postMessage({
       jsonrpc: '2.0',
       id: id,
       method: method,
       params: params
     }, '*');
   }
 
-  wnd.addEventListener('message', function (event) {
+  window.addEventListener('message', function (event) {
     var msg = event.data;
 
     if (msg.jsonrpc && !msg.method) {