[uber page] Update web-ui font settings

chrome/app/resources/locale_settings_mac.grd

 <?xml version="1.0" encoding="UTF-8"?>
 <grit latest_public_release="0" current_release="1">
   <outputs>
     <output filename="grit/platform_locale_settings.h" type="rc_header">
       <emit emit_type='prepend'></emit>
     </output>
     <output filename="platform_locale_settings_am.pak" type="data_package" lang="am" />
     <output filename="platform_locale_settings_ar.pak" type="data_package" lang="ar" />
     <output filename="platform_locale_settings_bg.pak" type="data_package" lang="bg" />
     <output filename="platform_locale_settings_bn.pak" type="data_package" lang="bn" />
@@ skipping 101 matching lines @@
     <file path="platform_locale_settings/locale_settings_mac_tr.xtb" lang="tr" />
     <file path="platform_locale_settings/locale_settings_mac_uk.xtb" lang="uk" />
     <file path="platform_locale_settings/locale_settings_mac_vi.xtb" lang="vi" />
     <file path="platform_locale_settings/locale_settings_mac_zh-CN.xtb" lang="zh-CN" />
     <file path="platform_locale_settings/locale_settings_mac_zh-TW.xtb" lang="zh-TW" />
   </translations>
   <release seq="1" allow_pseudo="false">
     <messages fallback_to_english="true">
       <!-- The font used in Web UI (e.g. History). -->
       <message name="IDS_WEB_FONT_FAMILY" use_name_for_id="true">
-        Helvetica, sans-serif
+        'Open Sans', Helvetica, sans-serif
       </message>
 
       <!-- The relative font size in % used in Web UI (e.g. History).  -->
       <message name="IDS_WEB_FONT_SIZE" use_name_for_id="true">
-        84%
+        75%
       </message>
 
       <!-- The default value for |WebPreference::standard_font_family| -->
       <message name="IDS_STANDARD_FONT_FAMILY" use_name_for_id="true">
         Times
       </message>
 
       <!-- The default value for |WebPreference::fixed_font_family| -->
       <message name="IDS_FIXED_FONT_FAMILY" use_name_for_id="true">
         Courier
@@ skipping 112 matching lines @@
         0
       </message>
 
       <!-- The default value for |WebPreference::minimum_logical_font_size|. -->
       <message name="IDS_MINIMUM_LOGICAL_FONT_SIZE" use_name_for_id="true">
         9
       </message>
     </messages>
   </release>
 </grit>