Fix: Prevent negative timing data

doc/README_CN.md

@@ -49,7 +49,7 @@ Eruda 是一个专为手机网页前端设计的调试面板，类似 DevTools
 通过CDN使用：
 
 ```html
-<script src="//cdn.bootcss.com/eruda/1.2.6/eruda.min.js"></script>
+<script src="//cdn.bootcss.com/eruda/1.3.0/eruda.min.js"></script>
 <script>eruda.init();</script>
 ```
 

doc/UTIL_API.md

@@ -1743,6 +1743,21 @@ query.stringify({foo: 'bar', eruda: 'true'}); // -> 'foo=bar&eruda=true'
 query.parse('name=eruda&name=eustia'); // -> {name: ['eruda', 'eustia']}
 ```
 
+## ready 
+
+Invoke callback when dom is ready, similar to jQuery ready.
+
+|Name|Type    |Desc             |
+|----|--------|-----------------|
+|fn  |function|Callback function|
+
+```javascript
+ready(function ()
+{
+    // It's safe to manipulate dom here.
+});
+```
+
 ## repeat 
 
 Repeat string n-times.

src/Network/Network.js

@@ -336,7 +336,7 @@ export default class Network extends Tool
 
         if (!cfg.get('disablePerformance'))
         {
-            this._getPerformanceTimingData();
+            util.ready(() => this._getPerformanceTimingData());
             renderData.data = this._performanceTimingData;
             renderData.timing = this._performanceTiming;
         }

src/lib/util.js

@@ -5401,6 +5401,55 @@ module.exports = (function ()
         return exports;
     })();
 
+    /* ------------------------------ ready ------------------------------ */
+
+    _.ready = (function ()
+    {
+        /* Invoke callback when dom is ready, similar to jQuery ready.
+         *
+         * |Name|Type    |Desc             |
+         * |----|--------|-----------------|
+         * |fn  |function|Callback function|
+         *
+         * ```javascript
+         * ready(function ()
+         * {
+         *     // It's safe to manipulate dom here.
+         * });
+         * ```
+         */
+
+        /* module
+         * env: browser
+         * test: browser
+         */
+
+        var fns = [],
+            listener,
+            doc = document,
+            hack = doc.documentElement.doScroll,
+            domContentLoaded = 'DOMContentLoaded',
+            loaded = (hack ? /^loaded|^c/ : /^loaded|^i|^c/).test(doc.readyState);
+
+        if (!loaded)
+        {
+            doc.addEventListener(domContentLoaded, listener = function ()
+            {
+                doc.removeEventListener(domContentLoaded, listener);
+                loaded = 1;
+                /* eslint-disable no-cond-assign */
+                while (listener = fns.shift()) listener();
+            });
+        }
+
+        function exports(fn)
+        {
+            loaded ? setTimeout(fn, 0) : fns.push(fn)
+        }
+
+        return exports;
+    })();
+
     /* ------------------------------ rtrim ------------------------------ */
 
     var rtrim = _.rtrim = (function ()