Revert of Fix GN build on Linux ChromiumOS

Revert of Fix GN build on Linux ChromiumOS (patchset #1 id:1 of https://codereview.chromium.org/816393003/)

Reason for revert:
This broke the GN compile on chromeos:
http://build.chromium.org/p/chromium.chromiumos/buildstatus?builder=Linux%20ChromiumOS%20GN&number=5300

Original issue's description:
> Fix GN build on Linux ChromiumOS
>
> This is a fix for Linux ChromiumOS GN build:
> http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20GN/builds/5292
>
> "view_event_test_platform_part_ash.cc" is not in 'sources'.
>
> BUG=n/a
> TEST=build
> TBR=brettw@chromium.org
> NOTRY=true
>
> Committed: https://crrev.com/45dcea9064c39161b112b1810e78de13b044e991
> Cr-Commit-Position: refs/heads/master@{#310050}

TBR=brettw@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=n/a

Committed: https://crrev.com/7a2071d1d2a1b7aafb5fbba3b802100d2a3661e8
Cr-Commit-Position: refs/heads/master@{#310053}

[nhiroki, 2015-01-06 04:48:53]

Created Revert of Fix GN build on Linux ChromiumOS

[commit-bot: I haz the power, 2015-01-06 04:49:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/794053007/1

[commit-bot: I haz the power, 2015-01-06 04:50:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-06 04:50:55]

Patchset 1 (id:??) landed as
https://crrev.com/7a2071d1d2a1b7aafb5fbba3b802100d2a3661e8
Cr-Commit-Position: refs/heads/master@{#310053}