[cr elements] icon buttons under toolbar have white focus circle

ui/webui/resources/cr_elements/cr_toolbar/cr_toolbar.html

 <link rel="import" href="chrome://resources/html/polymer.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/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_toolbar/cr_toolbar_search_field.html">
 
 <dom-module id="cr-toolbar">
   <template>
     <style>
       :host {
         --cr-toolbar-field-width: 580px;
         --cr-toolbar-height: 56px;
+        --paper-icon-button-ink-color: white;

[Dan Beam, 2017/03/27 12:13:05]

note: it'd be nice if you somehow joined with the "color: #fff" below by making
them a variable, maybe figuring out how to set --primary-text-color: white; or
some other means.

most ripples just set their background color from "currentcolor", but
paper-icon-button seems to be a special flower in this regard.

https://developer.mozilla.org/en-US/docs/Web/CSS/color_value#currentcolor_key...

         align-items: center;
         color: #fff;
         display: flex;
         height: var(--cr-toolbar-height);
       }
 
       h1 {
         -webkit-margin-start: 6px;
         -webkit-padding-end: 12px;
         flex: 1;
@@ skipping 133 matching lines @@
       <iron-media-query query="(max-width: 900px)" query-matches="{{narrow_}}">
       </iron-media-query>
     </div>
 
     <div id="rightContent">
       <content select=".more-actions"></content>
     </div>
   </template>
   <script src="cr_toolbar.js"></script>
 </dom-module>