Don't import win32gui when it's not needed

Don't import win32gui when it's not needed

If --parent-window=... isn't passed, then parent_window will be None,
and importing win32gui then is unnecessary.

Committed: https://crrev.com/2bf84ec90a3deb73607f561be67c531726254818
Cr-Commit-Position: refs/heads/master@{#348914}

[fs, 2015-09-11 15:51:47]

fs@opera.com changed reviewers:
+ sergeyu@chromium.org

[Sergey Ulanov, 2015-09-11 18:25:51]

LGTM

what's the reason --parent-window is missing?

[fs, 2015-09-14 07:38:46]

On 2015/09/11 18:25:51, Sergey Ulanov wrote:
...
> what's the reason --parent-window is missing?

I haven't managed to recall what the actual problem was, but it did help with
some problems during our testing.

[fs, 2015-09-15 15:27:39]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2015-09-15 15:28:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1335993002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1335993002/1

[commit-bot: I haz the power, 2015-09-15 17:00:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-15 17:01:23]

Patchset 1 (id:??) landed as
https://crrev.com/2bf84ec90a3deb73607f561be67c531726254818
Cr-Commit-Position: refs/heads/master@{#348914}

[commit-bot: I haz the power, 2015-09-23 12:46:08]

Patchset 1 (id:??) landed as
https://crrev.com/2bf84ec90a3deb73607f561be67c531726254818
Cr-Commit-Position: refs/heads/master@{#348914}