Add google analytics.

Author: csyonghe

_layouts/default.html

@@ -10,7 +10,14 @@
     <!--[if lt IE 9]>
     <script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
     <![endif]-->
-
+    <!-- Google tag (gtag.js) -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-TMTZVLLMBP"></script>
+    <script>
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+      gtag('config', 'G-TMTZVLLMBP');
+    </script>
 {% seo %}
   </head>
 
@@ -58,16 +65,5 @@
 
       </div>
     </div>
-
-    {% if site.google_analytics %}
-      <script>
-        (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
-        (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
-        m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
-        })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
-        ga('create', '{{ site.google_analytics }}', 'auto');
-        ga('send', 'pageview');
-      </script>
-    {% endif %}
   </body>
 </html>

_layouts/documentation.html

@@ -6,6 +6,13 @@
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <link rel="stylesheet" href="{{ '/assets/css/style.css?v=' | append: site.github.build_revision | relative_url }}">
     <link rel="stylesheet" type="text/css" href="{{ '/assets/css/print.css' | relative_url }}" media="print">
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-TMTZVLLMBP"></script>
+    <script>
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+      gtag('config', 'G-TMTZVLLMBP');
+    </script>
     <!--[if lt IE 9]>
     <script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
     <![endif]-->
@@ -76,16 +83,5 @@ <h1>User Guide to Slang</h1>
 
       </div>
     </div>
-
-    {% if site.google_analytics %}
-      <script>
-        (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
-        (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
-        m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
-        })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
-        ga('create', '{{ site.google_analytics }}', 'auto');
-        ga('send', 'pageview');
-      </script>
-    {% endif %}
   </body>
 </html>