Make Git revision dropdown style consistent

app/assets/stylesheets/framework/dropdowns.scss

@@ -725,9 +725,9 @@
 }
 // TODO: change global style and remove mixin
-@mixin new-style-dropdown {
-  .dropdown-menu,
-  .dropdown-menu-nav {
+@mixin new-style-dropdown($selector: '') {
+  #{$selector}.dropdown-menu,
+  #{$selector}.dropdown-menu-nav {
     .divider {
       margin: 6px 0;
     }
@@ -773,7 +773,7 @@
     }
   }
-  .dropdown-menu-align-right {
+  #{$selector}.dropdown-menu-align-right {
     margin-top: 2px;
   }
 }

app/assets/stylesheets/framework/typography.scss

@@ -339,6 +339,8 @@ a > code {
   @extend .ref-name;
 }
+@include new-style-dropdown('.git-revision-dropdown');
+
 /**
  * Apply Markdown typography
  *