[MD History] Color tweaks.

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/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://resources/polymer/v1_0/iron-scroll-target-behavior/iron-scroll-target-behavior.html">
 <link rel="import" href="chrome://history/history_toolbar.html">
 <link rel="import" href="chrome://history/list_container.html">
 <link rel="import" href="chrome://history/router.html">
 <link rel="import" href="chrome://history/shared_style.html">
 <link rel="import" href="chrome://history/side_bar.html">
 <link rel="stylesheet" href="chrome://resources/css/md_colors.css">
 
 <!-- Lazy loaded: history-synced-device-manager, app-drawer. -->
 
 <dom-module id="history-app">
   <template>
     <style include="shared-style">
       :host {
+        color: var(--primary-text-color);
         display: block;
         height: 100%;
         overflow: hidden;
         z-index: 0;
       }
 
       history-toolbar {
         background: var(--md-toolbar-color);
         z-index: 2;
       }
@@ skipping 26 matching lines @@
       #drawer:unresolved {
         display: none;
       }
 
       #drawer {
         z-index: 3;
       }
 
       #drawer-header {
         align-items: center;
-        border-bottom: 1px solid rgba(0, 0, 0, 0.08);
+        border-bottom: 1px solid var(--separator-color);
         box-sizing: border-box;
         display: flex;
         height: var(--toolbar-height);
       }
 
       h1 {
         -webkit-padding-start: 24px;
-        color: rgb(66, 66, 66);
+        color: var(--primary-text-color);
         font-size: 123%;
         font-weight: 400;
       }
 
       #drop-shadow {
         box-shadow: inset 0 5px 6px -3px rgba(0, 0, 0, 0.4);
         height: 6px;
         left: 0;
         opacity: 0;
         pointer-events: none;
@@ skipping 62 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>