Add missing fling_curve* entries to GN events targets.

Add missing fling_curve* entries to GN events targets.

This is so it matches with GYP version. This was reported by
http://build.chromium.org/p/chromium.linux/builders/Linux%20GN/builds/12122/steps/gyp_flag_compare/logs/stdio

BUG=None
TEST=gn gen out_gn/Debug && ninja -C out_gn/Debug events_base
events_unittests
R=brettw@chromium.org
TBR=sky@chromium.org

Committed: https://crrev.com/6a528cdd4d2878e61fcd41aa2137c153398b822f
Cr-Commit-Position: refs/heads/master@{#295881}

[tfarina, 2014-09-19 01:55:40]

PTAL.

[tfarina, 2014-09-19 17:12:03]

Ping.

Scott, I need your approval for ui/.

Thanks.

[brettw, 2014-09-19 17:25:18]

brettw@chromium.org changed reviewers:
+ brettw@chromium.org

[brettw, 2014-09-19 17:25:18]

lgtm

[tfarina, 2014-09-19 20:29:55]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2014-09-19 20:31:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/587533002/1

[commit-bot: I haz the power, 2014-09-19 20:53:03]

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

[commit-bot: I haz the power, 2014-09-19 20:53:05]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[tfarina, 2014-09-20 17:40:49]

tfarina@chromium.org changed reviewers:
- scottmg@chromium.org

[tfarina, 2014-09-20 17:40:49]

TBR sky for this.

[tfarina, 2014-09-20 17:41:57]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2014-09-20 17:42:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/587533002/1

[commit-bot: I haz the power, 2014-09-20 17:48:34]

Committed patchset #1 (id:1) as 210575ec17dcaae32aff52df5dba15f0c096a335

[commit-bot: I haz the power, 2014-09-20 17:49:07]

Patchset 1 (id:??) landed as
https://crrev.com/6a528cdd4d2878e61fcd41aa2137c153398b822f
Cr-Commit-Position: refs/heads/master@{#295881}