Fix crash when AppBannerClient is null when resolveBeforeInstallPromptPromise is called.

Fix crash when AppBannerClient is null when resolveBeforeInstallPromptPromise is called.

The crash is a regression from:
https://codereview.chromium.org/1807643002

There is now a simple layout test preventing a similar regression.

BUG=601480
R=jochen@chromium.org

Committed: https://crrev.com/005172539b5aefaa52273ebe784f14e2bb16d15a
Cr-Commit-Position: refs/heads/master@{#387326}

[mlamouri (slow - plz ping), 2016-04-13 13:33:15]

The CQ bit was checked by mlamouri@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-04-13 13:33:34]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1886763002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1886763002/20001

[commit-bot: I haz the power, 2016-04-13 14:42:25]

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

[commit-bot: I haz the power, 2016-04-13 14:42:26]

Dry run: This issue passed the CQ dry run.

[jochen (gone - plz use gerrit), 2016-04-14 13:40:08]

lgtm

[mlamouri (slow - plz ping), 2016-04-14 13:40:16]

The CQ bit was checked by mlamouri@chromium.org

[commit-bot: I haz the power, 2016-04-14 13:40:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1886763002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1886763002/20001

[commit-bot: I haz the power, 2016-04-14 15:50:53]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-04-14 15:52:01]

Description was changed from

==========
Fix crash when AppBannerClient is null when resolveBeforeInstallPromptPromise is
called.

The crash is a regression from:
https://codereview.chromium.org/1807643002

There is now a simple layout test preventing a similar regression.

BUG=601480
R=jochen@chromium.org
==========

to

==========
Fix crash when AppBannerClient is null when resolveBeforeInstallPromptPromise is
called.

The crash is a regression from:
https://codereview.chromium.org/1807643002

There is now a simple layout test preventing a similar regression.

BUG=601480
R=jochen@chromium.org

Committed: https://crrev.com/005172539b5aefaa52273ebe784f14e2bb16d15a
Cr-Commit-Position: refs/heads/master@{#387326}
==========

[commit-bot: I haz the power, 2016-04-14 15:52:02]

Patchset 2 (id:??) landed as
https://crrev.com/005172539b5aefaa52273ebe784f14e2bb16d15a
Cr-Commit-Position: refs/heads/master@{#387326}