Make theme selector button visible even for non-local pages

Author: GuillaumeGomez

src/librustdoc/html/static/js/main.js

@@ -135,15 +135,10 @@ function hideThemeButtonState() {
 
 // Set up the theme picker list.
 (function () {
-    if (!document.location.href.startsWith("file:///")) {
-        return;
-    }
     var themeChoices = getThemesElement();
     var themePicker = getThemePickerElement();
     var availableThemes = getVar("themes").split(",");
 
-    removeClass(themeChoices.parentElement, "hidden");
-
     function switchThemeButtonState() {
         if (themeChoices.style.display === "block") {
             hideThemeButtonState();

src/librustdoc/html/templates/page.html

@@ -108,7 +108,7 @@ <h2 class="location"></h2>
                     {%- endif -%}
                 </a> {#- -#}
                 <nav class="sub"> {#- -#}
-                    <div class="theme-picker hidden"> {#- -#}
+                    <div class="theme-picker"> {#- -#}
                         <button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu" title="themes"> {#- -#}
                             <img width="22" height="22" alt="Pick another theme!" {# -#}
                              src="{{static_root_path|safe}}brush{{page.resource_suffix}}.svg"> {#- -#}