VR: Use system back button behaviour while in ChromeTabbedActivity.

VR: Use system back button behaviour while in ChromeTabbedActivity.

This allows us to behave the same way CTA does when hitting the back button,
which includes closing tabs opened by links. However, we disable exiting
chrome when the back stack is exhausted.

This is important because we don't support manual tab management yet in VR,
so we don't want users to get stuck after a link opens in a new tab.

Bug: 728725
Change-Id: I5c042bd9f902fdee3db56451de97fe944dcf293d
Reviewed-on: https://chromium-review.googlesource.com/519802
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>;
Reviewed-by: Yash Malik <ymalik@chromium.org>;
Reviewed-by: Ted Choc <tedchoc@chromium.org>;
Cr-Original-Commit-Position: refs/heads/master@{#476760}
Review-Url: https://codereview.chromium.org/2924593002 .
Cr-Commit-Position: refs/branch-heads/3112@{#151}
Cr-Branched-From: b6460e24cf59f429d69de255538d0fc7a425ccf9-refs/heads/master@{#474897}
Committed: https://chromium.googlesource.com/chromium/src/+/2c81bbb26501c9f5dfa48abefd9c8b80dd161e5c

[mthiesse, 2017-06-05 14:36:00]

Description was changed from

==========
VR: Use system back button behaviour while in ChromeTabbedActivity.

This allows us to behave the same way CTA does when hitting the back button,
which includes closing tabs opened by links. However, we disable exiting
chrome when the back stack is exhausted.

This is important because we don't support manual tab management yet in VR,
so we don't want users to get stuck after a link opens in a new tab.

Bug: 728725
Change-Id: I5c042bd9f902fdee3db56451de97fe944dcf293d
Reviewed-on: https://chromium-review.googlesource.com/519802
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Reviewed-by: Yash Malik <ymalik@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#476760}
(cherry picked from commit 2537fa873c33c1c2597b2f03d7a15d7c88d1da3e)
==========

to

==========
VR: Use system back button behaviour while in ChromeTabbedActivity.

This allows us to behave the same way CTA does when hitting the back button,
which includes closing tabs opened by links. However, we disable exiting
chrome when the back stack is exhausted.

This is important because we don't support manual tab management yet in VR,
so we don't want users to get stuck after a link opens in a new tab.

Bug: 728725
Change-Id: I5c042bd9f902fdee3db56451de97fe944dcf293d
Reviewed-on: https://chromium-review.googlesource.com/519802
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Reviewed-by: Yash Malik <ymalik@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#476760}
Review-Url: https://codereview.chromium.org/2924593002 .
Cr-Commit-Position: refs/branch-heads/3112@{#151}
Cr-Branched-From:
b6460e24cf59f429d69de255538d0fc7a425ccf9-refs/heads/master@{#474897}
Committed:
https://chromium.googlesource.com/chromium/src/+/2c81bbb26501c9f5dfa48abefd9c...
==========

[mthiesse, 2017-06-05 14:36:02]

Committed patchset #1 (id:1) manually as
2c81bbb26501c9f5dfa48abefd9c8b80dd161e5c.