Clean up Noto Sans UI stuff.

ui/strings/app_locale_settings.grd

Index: ui/strings/app_locale_settings.grd
diff --git a/ui/strings/app_locale_settings.grd b/ui/strings/app_locale_settings.grd
index 920e72d0a60d29e8b72d73f4ea0186b4a413a5cb..effb2d67f600737a371e85a29770376aae4c594c 100644
--- a/ui/strings/app_locale_settings.grd
+++ b/ui/strings/app_locale_settings.grd
@@ -256,19 +256,15 @@
       <if expr="chromeos">
         <!-- The font name like: 'Font Name, 12px' -->
         <message name="IDS_UI_FONT_FAMILY_CROS" use_name_for_id="true">
-          Noto Sans UI, 13px
+          Roboto, Noto Sans UI, 13px

[Avi (use Gerrit), 2015/05/06 22:00:02]

Given the environs, where Roboto will always be available, do we still want to
list Noto Sans?

[Daniel Erat, 2015/05/06 22:04:10]

jungshik can confirm, but i believe that noto sans ui's coverage vastly exceeds
roboto's. if that's correct, we probably want to use it for fallback.

[Avi (use Gerrit), 2015/05/06 22:06:18]

But then, in all those other files, you're changing the size too. If for some of
those regions you're going to definitely hit Noto Sans because of the lack of
code point coverage, this then turns out to be a UI-affecting change.

[Daniel Erat, 2015/05/06 22:10:32]

you're right. the currently checked-in (and shipping) code calls
ReplaceNotoSansWithRobotoIfEnabled() to replace "Noto Sans UI" with "Roboto" in
these strings, so this change should probably do the same.

[jungshik at Google, 2015/05/07 13:45:15]

Actually, Roboto (relatively new version of Roboto as checked in to Chrome OS
[1] ) matches or even exceeds the character repertoire of Noto Sans UI. So, for
languages written in LGC, we don't need 'Noto Sans UI' as a fallback. 


[1] There's an update delivered very recently and we have to update once more,
but what's checked in is 'recent' enough. 

[xdai1, 2015/05/08 22:22:14]

Done.

         </message>
 
         <!-- The font used in Web UI (e.g. History). -->
         <message name="IDS_WEB_FONT_FAMILY" use_name_for_id="true">
-          'Noto Sans UI', sans-serif
+          Roboto, 'Noto Sans UI', sans-serif

[Avi (use Gerrit), 2015/05/06 22:00:02]

ditto, plus the same question for all the other xtb files.

         </message>
 
         <!-- The relative font size in % used in Web UI (e.g. History).  -->
-        <!-- TODO(xdai): 80% is an appropriate size for Roboto, which is the
-             default as of M42, rather than for Noto Sans UI. This comment
-             should be deleted when the old Noto Sans UI code is removed; see
-             http://crbug.com/482042. -->
         <message name="IDS_WEB_FONT_SIZE" use_name_for_id="true">
           80%
         </message>