Remove trailing '\' to avoid build failure on gcc 4.x toolchain.

Remove trailing '\' to avoid build failure on gcc 4.x toolchain.

The trailing '\' on a comment line produces following error on gcc 4.8

chrome/browser/extensions/chrome_url_request_util.h:29:1:
    error: multi-line comment [-Werror=comment]

TBR=fsamuel@chromium.org, lfg@chromium.org, rockot@chromium.org
NOTRY=true

Committed: https://crrev.com/33f197bf06e457f0a2a3616f15e0f44683cc2a2c
Cr-Commit-Position: refs/heads/master@{#295278}

[vivekg, 2014-09-17 05:19:36]

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

[vivekg, 2014-09-17 05:19:36]

PTAL, thanks!

[vivekg, 2014-09-17 05:52:41]

The CQ bit was checked by vivekg@chromium.org

[vivekg, 2014-09-17 05:53:10]

The CQ bit was unchecked by vivekg@chromium.org

[lfg, 2014-09-17 15:19:17]

lfg@chromium.org changed reviewers:
+ rockot@chromium.org

[lfg, 2014-09-17 15:19:18]

lgtm

+rockot as I'm not an owner of those files.

[lfg, 2014-09-17 15:24:56]

The CQ bit was checked by lfg@chromium.org

[commit-bot: I haz the power, 2014-09-17 15:25:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/552103003/1

[commit-bot: I haz the power, 2014-09-17 15:26:28]

Committed patchset #1 (id:1) as 853bb84c352cec492b1473c32bc1cef241d533d4

[commit-bot: I haz the power, 2014-09-17 15:27:09]

Patchset 1 (id:??) landed as
https://crrev.com/33f197bf06e457f0a2a3616f15e0f44683cc2a2c
Cr-Commit-Position: refs/heads/master@{#295278}