Update Material Design History colors.

chrome/browser/resources/md_history/history_toolbar.html

 <link rel="import" href="chrome://resources/polymer/v1_0/polymer/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_search_field/cr_search_field.html">
 <link rel="import" href="chrome://history/shared_style.html">
 
 <dom-module id="history-toolbar">
   <template>
     <style include="shared-style"></style>
     <style>
       :host {
-        background: rgb(63, 85, 102);
+        background: rgb(52, 73, 94);
         color: #fff;
         height: 56px;
         transition: background-color 150ms;
       }
 
       :host,
       #items,
       #main-content,
       #button-container,
       #toolbar-container {
@@ skipping 81 matching lines @@
         <paper-button on-tap="onClearBrowsingDataTap_"
             id="clear-browsing-data-button">
           $i18n{clearBrowsingData}
         </paper-button>
       </div>
       <div id="back-padding"></div>
     </div>
   </template>
   <script src="chrome://history/history_toolbar.js"></script>
 </dom-module>