doc: hide video and share if being served from CN

In the case where requests are coming from mainland China, hide
links to locations that are blocked and functionality that is
not permitted.

Additionally, some very small cleanup of the JS.

This change requires https://go-review.googlesource.com/c/52873

Change-Id: I7fc68748e629dbe5b966d6bf117e7f7b546966eb
Reviewed-on: https://go-review.googlesource.com/52872
Reviewed-by: Chris Broadfoot <cbro@golang.org>

doc/root.html

@@ -6,7 +6,9 @@
 <div class="left">
 
 <div id="learn">
+{{if not $.GoogleCN}}
 <a class="popout share">Pop-out</a>
+{{end}}
 <div class="rootHeading">Try Go</div>
 <div class="input">
 <textarea spellcheck="false" class="code">// You can edit this code!
@@ -26,10 +28,10 @@ Hello, 世界
 </div>
 <div class="buttons">
 <a class="run" href="#" title="Run this code [shift-enter]">Run</a>
-{{if $.Share}}
+{{if not $.GoogleCN}}
 <a class="share" href="#" title="Share this code">Share</a>
-{{end}}
 <a class="tour" href="//tour.golang.org/" title="Learn Go from your browser">Tour</a>
+{{end}}
 </div>
 <div class="toys">
 <select>
@@ -68,27 +70,28 @@ Linux, Mac OS X, Windows, and more.
 
 <div style="clear: both"></div>
 
+{{if not $.GoogleCN}}
 <div class="left">
-
   <div id="video">
     <div class="rootHeading">Featured video</div>
     <iframe width="415" height="241" src="//www.youtube.com/embed/ytEkHepK08c" frameborder="0" allowfullscreen></iframe>
   </div>
-
 </div>
+{{end}}
 
-<div class="right">
+ <div {{if not $.GoogleCN}}class="right"{{end}}>
-
 	<div id="blog">
 		<div class="rootHeading">Featured articles</div>
 		<div class="read"><a href="//blog.golang.org/">Read more</a></div>
 	</div>
-
  </div>
 
+
 <div style="clear: both;"></div>
 
-<script type="text/javascript">
+<script>
+(function() {
+	'use strict';
 
   function readableTime(t) {
 		var m = ["January", "February", "March", "April", "May", "June", "July",
@@ -98,7 +101,7 @@ function readableTime(t) {
 		return d.getDate() + " " + m[d.getMonth()] + " " + d.getFullYear();
 	}
 
-function feedLoaded(result) {
+	window.feedLoaded = function(result) {
 		var blog = document.getElementById("blog");
 		var read = blog.getElementsByClassName("read")[0];
 		for (var i = 0; i < result.length && i < 2; i++) {
@@ -138,7 +141,11 @@ window.initFuncs.push(function() {
 		$('<script/>').attr('text', 'text/javascript')
 			.attr('src', '//blog.golang.org/.json?jsonp=feedLoaded')
 			.appendTo('body');
+	});
 
+	{{if not $.GoogleCN}}
+
+	window.initFuncs.push(function() {
 		// Set the video at random.
 		var videos = [
 			{h: 241, s: "//www.youtube.com/embed/ytEkHepK08c"}, // Tour of Go
@@ -149,4 +156,6 @@ window.initFuncs.push(function() {
 		$('#video iframe').attr('height', v.h).attr('src', v.s);
 	});
 
+	{{end}}
+})();
 </script>