Rebaseline fast/ tests on Yosemite

Rebaseline fast/ tests on Yosemite

Also converting fast/forms/button-generated-content.html to use
the Ahem font, which eliminates a sub-pixel font-related issue
that was causing the ref test to fail on Yosemite.

BUG=509025
R=eae,joelo,ojan

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=200937

[eae, 2015-08-20 21:40:04]

LGTM

PDR=true

[eae, 2015-08-20 21:40:10]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2015-08-20 21:40:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1303943002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1303943002/1

[commit-bot: I haz the power, 2015-08-20 21:42:20]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-20 21:42:21]

Try jobs failed on following builders:
  ios_dbg_simulator_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_dbg_simulator...)
  ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[leviw_travelin_and_unemployed, 2015-08-20 21:49:18]

The CQ bit was checked by leviw@chromium.org

[leviw_travelin_and_unemployed, 2015-08-20 21:49:18]

The patchset sent to the CQ was uploaded after l-g-t-m from eae@chromium.org
Link to the patchset: https://codereview.chromium.org/1303943002/#ps20001
(title: "ToTed")

[commit-bot: I haz the power, 2015-08-20 21:49:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1303943002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1303943002/20001

[commit-bot: I haz the power, 2015-08-20 22:55:07]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=200937