Avoid hardcoded font families.

Avoid hardcoded font families.

BUG=303778
TEST=check Files.app, VideoPlayer.app, and AudioPlayer.app if fonts look same.

Committed: https://crrev.com/cd67920a6d1a6f91d807af50db1b2ca71290e7c5
Cr-Commit-Position: refs/heads/master@{#310743}

[fukino, 2015-01-08 08:33:40]

fukino@chromium.org changed reviewers:
+ yoshiki@chromium.org

[fukino, 2015-01-08 08:33:41]

yoshiki@, could you take a look? Thanks!

After Roboto is introduced, appropriate font family may vary depending on locale
settings.
This CL make file manager use platform's common style sheet instead of
specifying in CSS file explicitly.

A CL doing the same work: https://codereview.chromium.org/786023002

[yoshiki, 2015-01-09 08:24:15]

sorry for late. lgtm

[fukino, 2015-01-09 08:24:49]

On 2015/01/09 08:24:15, yoshiki wrote:
> sorry for late. lgtm

thanks!

[fukino, 2015-01-09 08:24:52]

The CQ bit was checked by fukino@chromium.org

[commit-bot: I haz the power, 2015-01-09 08:25:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/842813002/1

[commit-bot: I haz the power, 2015-01-09 09:06:44]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-09 09:07:27]

Patchset 1 (id:??) landed as
https://crrev.com/cd67920a6d1a6f91d807af50db1b2ca71290e7c5
Cr-Commit-Position: refs/heads/master@{#310743}