MD History: fix side nav layout in RTL

chrome/browser/resources/md_history/app.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/cr/ui.html">
 <link rel="import" href="chrome://resources/html/cr/ui/command.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/app-layout/app-drawer/app-drawer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/app-route/app-location.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/app-route/app-route.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-media-query/iron-media-query.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-pages/iron-pages.html">
 <link rel="import" href="chrome://history/history_toolbar.html">
 <link rel="import" href="chrome://history/list_container.html">
@@ skipping 10 matching lines @@
       }
     </style>
     <style include="shared-style">
       :host {
         display: block;
         height: 100%;
         overflow: hidden;
       }
 
       /* Sizing this with flex causes slow load performance, see
-         crbug.com/618153. */
+       * crbug.com/618153. TODO(dbeam): is this still an issue? */

[tsergeant, 2016/08/23 23:06:59]

It's not, I just haven't had a chance to get back to it yet.

       #main-container {
         height: calc(100% - var(--toolbar-height));
       }
 
       :host([grouped_]) #main-container {
         height: calc(100% - var(--toolbar-grouped-height));
       }
 
       #content-side-bar {
         float: left;
       }
 
+      :host-context([dir='rtl']) #content-side-bar {
+        float: right;
+      }
+
       #content,
       #content > * {
         height: 100%;
       }
 
       #drawer-header {
         align-items: center;
         border-bottom: 1px solid rgba(0, 0, 0, 0.08);
         display: flex;
         height: var(--toolbar-height);
@@ skipping 57 matching lines @@
         </history-side-bar>
       </app-drawer>
     </template>
 
     <iron-media-query query="(max-width: 1023px)"
         query-matches="{{hasDrawer_}}">
     </iron-media-query>
   </template>
   <script src="chrome://history/app.js"></script>
 </dom-module>