Remove unusued instance variable of chrome::VersionInfo.

Remove unusued instance variable of chrome::VersionInfo.

The instance variable chrome::VersionInfo::version_info_ is never used
and can be safely removed. Also remove the forward-declaration of the
FileVersionInfo class and the corresponding #include in the implementation
file.

BUG=None

Committed: https://crrev.com/1067392cb46b944e198f085fad7e226d700ad070
Cr-Commit-Position: refs/heads/master@{#339851}

[sdefresne, 2015-07-20 18:32:15]

sdefresne@chromium.org changed reviewers:
+ jhawkins@chromium.org

[sdefresne, 2015-07-20 18:32:15]

Please take a look.

[James Hawkins, 2015-07-21 19:04:43]

lgtm

[sdefresne, 2015-07-22 08:39:06]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2015-07-22 08:39:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1244773003/20001

[commit-bot: I haz the power, 2015-07-22 09:11:22]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-22 09:12:01]

Patchset 2 (id:??) landed as
https://crrev.com/1067392cb46b944e198f085fad7e226d700ad070
Cr-Commit-Position: refs/heads/master@{#339851}