X11: Fix msan use-of-uninitialized-value error

X11: Fix msan use-of-uninitialized-value error

BUG=None
R=erg@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng

Review-Url: https://codereview.chromium.org/2740933005
Cr-Commit-Position: refs/heads/master@{#456248}
Committed: https://chromium.googlesource.com/chromium/src/+/a417069dab92fa16d63553b39a898b2f5ed3851e

[Tom (Use chromium acct), 2017-03-11 00:17:46]

erg ptal

[Tom (Use chromium acct), 2017-03-11 00:19:15]

Description was changed from

==========
X11: Fix msan use-of-uninitialized-value error

BUG=None
R=erg@chromium.org
==========

to

==========
X11: Fix msan use-of-uninitialized-value error

BUG=None
R=erg@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng
==========

[Tom (Use chromium acct), 2017-03-11 00:19:19]

The CQ bit was checked by thomasanderson@google.com to run a CQ dry run

[commit-bot: I haz the power, 2017-03-11 00:19:43]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Elliot Glaysher, 2017-03-11 00:24:43]

lgtm

[Nico, 2017-03-11 00:40:44]

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

[Nico, 2017-03-11 00:40:44]

https://codereview.chromium.org/2740933005/diff/1/ui/views/widget/desktop_aur...
File ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc (right):

https://codereview.chromium.org/2740933005/diff/1/ui/views/widget/desktop_aur...
ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc:1681: XSizeHints
hints;
= {} here to zero out all the fields doesn't work?

[Tom (Use chromium acct), 2017-03-11 00:45:36]

https://codereview.chromium.org/2740933005/diff/1/ui/views/widget/desktop_aur...
File ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc (right):

https://codereview.chromium.org/2740933005/diff/1/ui/views/widget/desktop_aur...
ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc:1681: XSizeHints
hints;
On 2017/03/11 00:40:44, Nico wrote:
> = {} here to zero out all the fields doesn't work?

That would work too, but it's unnecessary because Xlib only reads fields in
XSizeHints if the appropriate bit is set in |flags|.

Having it this way ensures that msan errors will be detected in the case of
setting a big in |flags|, and forgetting to set the corresponding field.

[commit-bot: I haz the power, 2017-03-11 01:31:26]

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

[commit-bot: I haz the power, 2017-03-11 01:31:27]

Dry run: This issue passed the CQ dry run.

[Tom (Use chromium acct), 2017-03-11 01:32:28]

The CQ bit was checked by thomasanderson@google.com

[commit-bot: I haz the power, 2017-03-11 01:32:57]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-11 01:40:53]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1489195948197070, "parent_rev":
"141e9ca007617a802a8a22e5e8a635d2d4e7dcff", "commit_rev":
"a417069dab92fa16d63553b39a898b2f5ed3851e"}

[commit-bot: I haz the power, 2017-03-11 01:42:18]

Description was changed from

==========
X11: Fix msan use-of-uninitialized-value error

BUG=None
R=erg@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng
==========

to

==========
X11: Fix msan use-of-uninitialized-value error

BUG=None
R=erg@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng

Review-Url: https://codereview.chromium.org/2740933005
Cr-Commit-Position: refs/heads/master@{#456248}
Committed:
https://chromium.googlesource.com/chromium/src/+/a417069dab92fa16d63553b39a89...
==========

[commit-bot: I haz the power, 2017-03-11 01:42:19]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/a417069dab92fa16d63553b39a89...