Add missing NULL checks to NativeViewAccessibilityWin.

Add missing NULL checks to NativeViewAccessibilityWin.

IAccessible objects are reference-counted, so the COM object
may persist if the view is deleted. We should always check the
view (which will be nulled when the view is deleted).

BUG=436074
Committed: https://crrev.com/6b6714d20c8311b0b0badff0cd783eb6a4bff4bc
Cr-Commit-Position: refs/heads/master@{#313792}

[dmazzoni, 2015-01-23 19:25:20]

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

[dmazzoni, 2015-01-28 21:31:08]

dmazzoni@chromium.org changed reviewers:
+ cpu@chromium.org, dtseng@chromium.org

[dmazzoni, 2015-01-28 21:31:09]

Adding additional reviewers

[ananta, 2015-01-28 21:32:37]

https://codereview.chromium.org/872683005/diff/1/ui/views/accessibility/nativ...
File ui/views/accessibility/native_view_accessibility_win.cc (right):

https://codereview.chromium.org/872683005/diff/1/ui/views/accessibility/nativ...
ui/views/accessibility/native_view_accessibility_win.cc:1222: if (!provider)
Incorrect check? No provider here,

[dmazzoni, 2015-01-28 21:47:22]

https://codereview.chromium.org/872683005/diff/1/ui/views/accessibility/nativ...
File ui/views/accessibility/native_view_accessibility_win.cc (right):

https://codereview.chromium.org/872683005/diff/1/ui/views/accessibility/nativ...
ui/views/accessibility/native_view_accessibility_win.cc:1222: if (!provider)
On 2015/01/28 21:32:37, ananta wrote:
> Incorrect check? No provider here,

Oops, this should be |ret|. Compiles now.

[dmazzoni, 2015-01-29 16:46:09]

Ping

[ananta, 2015-01-29 20:00:28]

lgtm

[cpu_(ooo_6.6-7.5), 2015-01-29 20:20:23]

lgtm

[cpu_(ooo_6.6-7.5), 2015-01-29 20:20:28]

The CQ bit was checked by cpu@chromium.org

[commit-bot: I haz the power, 2015-01-29 20:20:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/872683005/20001

[commit-bot: I haz the power, 2015-01-29 21:15:46]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-29 21:18:05]

Patchset 2 (id:??) landed as
https://crrev.com/6b6714d20c8311b0b0badff0cd783eb6a4bff4bc
Cr-Commit-Position: refs/heads/master@{#313792}