Remove hard-coded font families in WebUI.

chrome/browser/resources/chromeos/login/oobe_screen_host_pairing.html

 <link rel="import" href="chrome://oobe/custom_elements.html">
 <link rel="import" href="chrome://resources/polymer/core-animated-pages/core-animated-pages.html">
 <link rel="import" href="chrome://resources/polymer/core-iconset-svg/core-iconset-svg.html">
 <link rel="import" href="chrome://resources/polymer/core-item/core-item.html">
 <link rel="import" href="chrome://resources/polymer/polymer/polymer.html">
 
 <core-iconset-svg id="host-pairing-icons" iconSize="48">
   <svg>
     <defs>
       <g id="cast">
         <include src="../../../../app/theme/cast_icon.svg">
       </g>
     </defs>
   </svg>
 </core-iconset-svg>
 
 <polymer-element name="host-pairing-page" noscript>
   <template>
+    <link rel="stylesheet" href="chrome://resources/css/text_defaults.css">  

[Dan Beam, 2014/12/10 19:49:24]

should we make text_defaults.css reach into shadow doms?  I guess not...

[xdai1, 2014/12/11 02:59:21]

Moved to front.

     <link rel="stylesheet" href="oobe_screen_host_pairing_page.css">
 
     <div id="title">
       <content select=".title"></content>
     </div>
     <div id="content">
       <content></content>
     </div>
   </template>
 </polymer-element>
 
 <polymer-element name="host-pairing-screen" extends="oobe-screen">
   <template>
+    <link rel="stylesheet" href="chrome://resources/css/text_defaults.css">
     <link rel="stylesheet" href="oobe_screen_host_pairing.css">
 
     <core-animated-pages transitions="cross-fade-all"
                          selected="{{C.page}}">
       <host-pairing-page name="welcome">
         <div class="title">{{'welcomeTitle' | i18n}}</div>
         <div>{{'welcomeText' | i18n}}</div>
       </host-pairing-page>
       <host-pairing-page name="code-confirmation">
         <div class="title">{{'confirmationTitle' | i18n}}</div>
@@ skipping 30 matching lines @@
       <div id="device-label">{{C.deviceName}}</div>
     </core-item>
     <div id="illustration"></div>
   </template>
 </polymer-element>
 
 <div class="step hidden no-logo fullscreen" id="host-pairing" hidden>
   <host-pairing-screen name="HostPairingScreen"></host-pairing-screen>
 </div>