Assert if we try to access another AX attribute while a layout is pending.

Assert if we try to access another AX attribute while a layout is pending.

Actual fix for crash is in https://codereview.chromium.org/469803003

BUG=393829
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180739

[dglazkov, 2014-08-13 22:37:25]

lgtm

[dmazzoni, 2014-08-13 22:58:36]

The CQ bit was checked by dmazzoni@chromium.org

[commit-bot: I haz the power, 2014-08-13 23:00:05]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dmazzoni@chromium.org/465143003/1

[commit-bot: I haz the power, 2014-08-14 03:36:28]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/2...)
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/2...)
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/19755)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/22671)

[commit-bot: I haz the power, 2014-08-14 04:16:13]

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

[commit-bot: I haz the power, 2014-08-14 04:16:14]

Try jobs failed on following builders:
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/22689)

[dmazzoni, 2014-08-20 23:41:22]

The CQ bit was checked by dmazzoni@chromium.org

[commit-bot: I haz the power, 2014-08-20 23:41:55]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dmazzoni@chromium.org/465143003/1

[commit-bot: I haz the power, 2014-08-20 23:47:50]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/2...)
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/2...)
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/20630)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/23757)

[commit-bot: I haz the power, 2014-08-20 23:49:47]

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

[commit-bot: I haz the power, 2014-08-20 23:49:48]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/20631)

[dmazzoni, 2014-08-21 16:21:44]

The CQ bit was checked by dmazzoni@chromium.org

[commit-bot: I haz the power, 2014-08-21 16:23:36]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dmazzoni@chromium.org/465143003/20001

[commit-bot: I haz the power, 2014-08-21 21:04:14]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_chromium_gn_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_chromium_gn_rel/bu...)

[commit-bot: I haz the power, 2014-08-21 21:43:25]

Committed patchset #2 (20001) as 180739