Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN, which could destroy the window and in
turn the HWNDMessageHandler instance.

Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc call.

BUG=581341
TEST=Covered by views_unittest WidgetTest.DestroyInSysCommandNCLButtonDownOnCaption

Committed: https://crrev.com/a54e6c0cb503d67d3eb086f936bc0429825d0c3b
Cr-Commit-Position: refs/heads/master@{#371892}

[ananta, 2016-01-27 01:54:30]

ananta@chromium.org changed reviewers:
+ sky@chromium.org

[sky, 2016-01-27 02:49:48]

LGTM

[ananta, 2016-01-27 02:50:15]

Description was changed from

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call which destroyed
the window and in turn the HWNDMessageHandler instance.

Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
==========

to

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN,
which could destroy the window and in
turn the HWNDMessageHandler instance.
 
Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
==========

[ananta, 2016-01-27 02:50:57]

Description was changed from

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN,
which could destroy the window and in
turn the HWNDMessageHandler instance.
 
Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
==========

to

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN,
which could destroy the window and in
turn the HWNDMessageHandler instance.
 
Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
TEST=Covered by views_unittest
WidgetTest.DestroyInSysCommandNCLButtonDownOnCaption
==========

[ananta, 2016-01-27 02:52:02]

On 2016/01/27 02:49:48, sky wrote:
> LGTM

Thanks. I added a views test. PTAL.

[sky, 2016-01-27 03:14:31]

SLGTM

https://codereview.chromium.org/1636183003/diff/20001/ui/views/widget/widget_...
File ui/views/widget/widget_unittest.cc (right):

https://codereview.chromium.org/1636183003/diff/20001/ui/views/widget/widget_...
ui/views/widget/widget_unittest.cc:3268: if (instance_->destroy_on_message_ &&
Is there a reason for this check? Doesn't the next line cover what you want?

https://codereview.chromium.org/1636183003/diff/20001/ui/views/widget/widget_...
ui/views/widget/widget_unittest.cc:3280: unsigned int destroy_on_message_;
nit: I first took this to mean destroy on any message, but it means destroy on a
specific message. So, how about message_to_destroy_on_?

[ananta, 2016-01-27 21:23:31]

https://codereview.chromium.org/1636183003/diff/20001/ui/views/widget/widget_...
File ui/views/widget/widget_unittest.cc (right):

https://codereview.chromium.org/1636183003/diff/20001/ui/views/widget/widget_...
ui/views/widget/widget_unittest.cc:3268: if (instance_->destroy_on_message_ &&
On 2016/01/27 03:14:30, sky wrote:
> Is there a reason for this check? Doesn't the next line cover what you want?

Yeah. Wrote that thinking about WM_NULL. Not needed.

https://codereview.chromium.org/1636183003/diff/20001/ui/views/widget/widget_...
ui/views/widget/widget_unittest.cc:3280: unsigned int destroy_on_message_;
On 2016/01/27 03:14:30, sky wrote:
> nit: I first took this to mean destroy on any message, but it means destroy on
a
> specific message. So, how about message_to_destroy_on_?

Done.

[ananta, 2016-01-27 21:33:13]

The CQ bit was checked by ananta@chromium.org

[ananta, 2016-01-27 21:33:14]

The patchset sent to the CQ was uploaded after l-g-t-m from sky@chromium.org
Link to the patchset: https://codereview.chromium.org/1636183003/#ps40001
(title: "Address review comments")

[ananta, 2016-01-27 21:33:16]

The CQ bit was unchecked by ananta@chromium.org

[ananta, 2016-01-27 21:34:29]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2016-01-27 21:36:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1636183003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1636183003/40001

[commit-bot: I haz the power, 2016-01-27 22:19:48]

Description was changed from

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN,
which could destroy the window and in
turn the HWNDMessageHandler instance.
 
Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
TEST=Covered by views_unittest
WidgetTest.DestroyInSysCommandNCLButtonDownOnCaption
==========

to

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN,
which could destroy the window and in
turn the HWNDMessageHandler instance.
 
Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
TEST=Covered by views_unittest
WidgetTest.DestroyInSysCommandNCLButtonDownOnCaption
==========

[commit-bot: I haz the power, 2016-01-27 22:19:49]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-01-27 22:20:31]

Description was changed from

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN,
which could destroy the window and in
turn the HWNDMessageHandler instance.
 
Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
TEST=Covered by views_unittest
WidgetTest.DestroyInSysCommandNCLButtonDownOnCaption
==========

to

==========
Fix crash in the HWNDMessageHandler::HandleMouseInputForCaption function.

Crash occurs because we are referencing a member variable
left_button_down_on_caption_ after the DefWindowProc call for WM_NCLBUTTONDOWN,
which could destroy the window and in
turn the HWNDMessageHandler instance.

Fix is to reset the left_button_down_on_caption_ member before the DefWindowProc
call.

BUG=581341
TEST=Covered by views_unittest
WidgetTest.DestroyInSysCommandNCLButtonDownOnCaption

Committed: https://crrev.com/a54e6c0cb503d67d3eb086f936bc0429825d0c3b
Cr-Commit-Position: refs/heads/master@{#371892}
==========

[commit-bot: I haz the power, 2016-01-27 22:20:32]

Patchset 3 (id:??) landed as
https://crrev.com/a54e6c0cb503d67d3eb086f936bc0429825d0c3b
Cr-Commit-Position: refs/heads/master@{#371892}