[fsp] Polish icons in Files app.

[fsp] Polish icons in Files app.

This patch makes the icons smaller plus fixes the mask, so they are always
white (except transparent pixels) when selected.

TBR=fukino@chromium.org
TEST=Tested manually with 3 different icons.
BUG=412602
Committed: https://crrev.com/05d0d0bf4f6f590c757d3ba4110d03dcad71c001
Cr-Commit-Position: refs/heads/master@{#302224}

[mtomasz, 2014-10-31 01:38:55]

mtomasz@chromium.org changed reviewers:
+ yawano@chromium.org

[mtomasz, 2014-10-31 01:39:03]

@yawano: PTAL. Thanks!

[yawano, 2014-10-31 02:54:50]

lgtm. Thank you!

[mtomasz, 2014-10-31 03:04:42]

On 2014/10/31 02:54:50, yawano wrote:
> lgtm. Thank you!

Thanks!

[mtomasz, 2014-10-31 04:15:51]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-10-31 04:16:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/693073002/1

[commit-bot: I haz the power, 2014-10-31 04:16:53]

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

[commit-bot: I haz the power, 2014-10-31 04:16:54]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[mtomasz, 2014-10-31 04:17:53]

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

[mtomasz, 2014-10-31 04:17:57]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-10-31 04:18:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/693073002/1

[commit-bot: I haz the power, 2014-10-31 04:59:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-31 05:00:19]

Patchset 1 (id:??) landed as
https://crrev.com/05d0d0bf4f6f590c757d3ba4110d03dcad71c001
Cr-Commit-Position: refs/heads/master@{#302224}