Makes loading test resources load the first supported scale factor

Makes loading test resources load the first supported scale factor

This is necessary as we don't always load 1x resources. In particular
when I run views_example_exe with --force-device-scale-factor=2 then
1x isn't loaded.

BUG=none
TEST=none
R=oshima@chromium.org

Committed: https://crrev.com/0362f6002609dca40e53dbc47b4e73b659a31164
Cr-Commit-Position: refs/heads/master@{#294196}

[oshima, 2014-09-10 17:26:43]

lgtm

[sky, 2014-09-10 17:27:56]

The CQ bit was checked by sky@chromium.org

[commit-bot: I haz the power, 2014-09-10 17:30:21]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/sky@chromium.org/564473002/1

[commit-bot: I haz the power, 2014-09-10 18:33:55]

Committed patchset #1 (id:1) as 3b09d34f8746ef787d6da81b4699562f93481dc4

[commit-bot: I haz the power, 2014-09-10 18:38:01]

Patchset 1 (id:??) landed as
https://crrev.com/0362f6002609dca40e53dbc47b4e73b659a31164
Cr-Commit-Position: refs/heads/master@{#294196}