Add Roboto-Medium webfont and factor out common Roboto WebUI CSS file.

ui/webui/resources/webui_resources.grd

 <?xml version="1.0" encoding="UTF-8"?>
 <!-- This comment is only here because changes to resources are not picked up
 without changes to the corresponding grd file. -->
 <grit latest_public_release="0" current_release="1">
   <outputs>
     <output filename="grit/webui_resources.h" type="rc_header">
       <emit emit_type='prepend'></emit>
     </output>
     <output filename="grit/webui_resources_map.cc"
             type="resource_file_map_source" />
     <output filename="grit/webui_resources_map.h" type="resource_map_header" />
     <output filename="webui_resources.pak" type="data_package" />
   </outputs>
   <release seq="1">
     <includes>
       <include name="IDR_WEBUI_I18N_TEMPLATE_JS" file="js/i18n_template.js" flattenhtml="true" type="BINDATA" />
       <include name="IDR_WEBUI_I18N_TEMPLATE_POLYMER_JS" file="js/i18n_template_polymer.js" flattenhtml="true" type="BINDATA" />
       <include name="IDR_WEBUI_JSTEMPLATE_JS" file="js/jstemplate_compiled.js" flattenhtml="true" type="BINDATA" />
       <include name="IDR_WEBUI_ANALYTICS_JS" file="js/analytics.js" flattenhtml="true" type="BINDATA" />
       <!-- Roboto Font -->
-      <include name="IDR_WEBUI_ROBOTO_ROBOTO_WOFF"  file="roboto/roboto.woff" type="BINDATA" />
-      <include name="IDR_WEBUI_ROBOTO_ROBOTO_WOFF2" file="roboto/roboto.woff2" type="BINDATA" /> 
+      <include name="IDR_WEBUI_ROBOTO_ROBOTO_REGULAR_LATIN_WOFF2" file="roboto/roboto-regular-latin.woff2" type="BINDATA" />
+      <include name="IDR_WEBUI_ROBOTO_ROBOTO_MEDIUM_LATIN_WOFF2" file="roboto/roboto-medium-latin.woff2" type="BINDATA" />
 
       <!-- Component apps common image resources - 1x -->
       <!-- White button -->
       <include name="IDR_WEBUI_IMAGES_APPS_BUTTON"
                file="../../resources/default_100_percent/common/button.png" type="BINDATA" />
       <include name="IDR_WEBUI_IMAGES_APPS_BUTTON_PRESSED"
                file="../../resources/default_100_percent/common/button_pressed.png" type="BINDATA" />
       <include name="IDR_WEBUI_IMAGES_APPS_BUTTON_HOVER"
                file="../../resources/default_100_percent/common/button_hover.png" type="BINDATA" />
       <include name="IDR_WEBUI_IMAGES_APPS_BUTTON_DISABLED"
@@ skipping 198 matching lines @@
                  file="css/menu.css" type="chrome_html"
                  flattenhtml="true" />
       <structure name="IDR_WEBUI_CSS_MENU_BUTTON"
                  file="css/menu_button.css" type="chrome_html"
                  flattenhtml="true" />
       <structure name="IDR_WEBUI_CSS_TEXT_DEFAULTS"
                  file="css/text_defaults.css" type="chrome_html" />
       <structure name="IDR_WEBUI_CSS_OVERLAY"
                  file="css/overlay.css" type="chrome_html"
                  flattenhtml="true" />
+      <structure name="IDR_WEBUI_CSS_ROBOTO"
+                 file="css/roboto.css" type="chrome_html" />
       <structure name="IDR_WEBUI_CSS_SPINNER"
                  file="css/spinner.css" type="chrome_html" />
       <structure name="IDR_WEBUI_CSS_TABLE"
                  file="css/table.css" type="chrome_html" />
       <structure name="IDR_WEBUI_CSS_TABS"
                  file="css/tabs.css" type="chrome_html" />
       <structure name="IDR_WEBUI_CSS_THROBBER"
                  file="css/throbber.css" type="chrome_html" />
       <structure name="IDR_WEBUI_CSS_TRASH"
                  file="css/trash.css" type="chrome_html" />
@@ skipping 139 matching lines @@
                    type="chrome_html" />
         <structure name="IDR_WEBUI_JS_UI_ACCOUNT_TWEAKS"
                    file="js/chromeos/ui_account_tweaks.js"
                    type="chrome_html" />
       </if>
       <part file="cr_elements_resources.grdp" />
       <part file="polymer_resources.grdp" />
     </structures>
   </release>
 </grit>