Refactor backdrop that is currently used in the maximized mode.

This is reland of crrev.com/2884623002.

Added test uncovered a stack-use-after-scope issue in AshTouchExplorationManager. Patch #2 fixes the issue.

Refactor backdrop that is currently used in the maximized mode.

The maximized mode creates a backdrop window so that a user will not see the content of windows behind the top window,
in case it doesn't cover the entire window. (can happen if the maximize size is specified for example)
This CL generalizes the backdrop code used in maximize mode as to create the backdrop in the following scenarios:

1) Has a aura::client::kHasBackdrop property = true.
2) BackdropDelegate::HasBackdrop(aura::Window* window) returns true.
3) Active ARC window when the spoken feedback is enabled.

* Added delegate to check if the window should have a backdrop.
  Maximized mode always puts a backdrop.

* Added kHasBackdrop property for a window that needs a backdrop even in clamshell.

* Move the accessibility feature implemented in exo's backbround. This
  is useful and should be there even for non-arc/exo case.

TBR=jamescook@chromium.org,reveman@chromium.org,sky@chromium.org
BUG=721646
TEST=coverted by unit tests

Review-Url: https://codereview.chromium.org/2884623002
Cr-Commit-Position: refs/heads/master@{#472401}
Committed: https://chromium.googlesource.com/chromium/src/+/04936c54ed2396ae54cd824e24f11151e0e11948

patch from issue 2884623002 at patchset 220001 (http://crrev.com/2884623002#ps220001)

Review-Url: https://codereview.chromium.org/2890733005
Cr-Commit-Position: refs/heads/master@{#472479}
Committed: https://chromium.googlesource.com/chromium/src/+/512e6cd623a2039889c13d04759dd6714c08f663

[oshima, 2017-05-17 15:37:43]

Description was changed from

==========
Refactor backdrop that is currently used in the maximized mode.

The maximized mode creates a backdrop window so that a user will not see the
content of windows behind the top window,
in case it doesn't cover the entire window. (can happen if the maximize size is
specified for example)
This CL generalizes the backdrop code used in maximize mode as to create the
backdrop in the following scenarios:

1) Has a aura::client::kHasBackdrop property = true.
2) BackdropDelegate::HasBackdrop(aura::Window* window) returns true.
3) Active ARC window when the spoken feedback is enabled.

* Added delegate to check if the window should have a backdrop.
  Maximized mode always puts a backdrop.

* Added kHasBackdrop property for a window that needs a backdrop even in
clamshell.

* Move the accessibility feature implemented in exo's backbround. This
  is useful and should be there even for non-arc/exo case.

BUG=721646
TEST=coverted by unit tests

Review-Url: https://codereview.chromium.org/2884623002
Cr-Commit-Position: refs/heads/master@{#472401}
Committed:
https://chromium.googlesource.com/chromium/src/+/04936c54ed2396ae54cd824e24f1...

patch from issue 2884623002 at patchset 220001
(http://crrev.com/2884623002#ps220001)
==========

to

==========
This is reland of crrev.com/2884623002.

Added test uncovered a stack-use-after-scope issue in
AshTouchExplorationManager. Patch #2 fixes the issue.

Refactor backdrop that is currently used in the maximized mode.

The maximized mode creates a backdrop window so that a user will not see the
content of windows behind the top window,
in case it doesn't cover the entire window. (can happen if the maximize size is
specified for example)
This CL generalizes the backdrop code used in maximize mode as to create the
backdrop in the following scenarios:

1) Has a aura::client::kHasBackdrop property = true.
2) BackdropDelegate::HasBackdrop(aura::Window* window) returns true.
3) Active ARC window when the spoken feedback is enabled.

* Added delegate to check if the window should have a backdrop.
  Maximized mode always puts a backdrop.

* Added kHasBackdrop property for a window that needs a backdrop even in
clamshell.

* Move the accessibility feature implemented in exo's backbround. This
  is useful and should be there even for non-arc/exo case.

TBR=jamescook@chromium.org,reveman@chromium.org,sky@chromium.org
BUG=721646
TEST=coverted by unit tests

Review-Url: https://codereview.chromium.org/2884623002
Cr-Commit-Position: refs/heads/master@{#472401}
Committed:
https://chromium.googlesource.com/chromium/src/+/04936c54ed2396ae54cd824e24f1...

patch from issue 2884623002 at patchset 220001
(http://crrev.com/2884623002#ps220001)
==========

[oshima, 2017-05-17 15:37:43]

oshima@chromium.org changed reviewers:
+ jamescook@chromium.org, reveman@chromium.org, sky@chromium.org

[oshima, 2017-05-17 15:37:58]

The CQ bit was checked by oshima@chromium.org

[commit-bot: I haz the power, 2017-05-17 15:38:24]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[James Cook, 2017-05-17 16:18:02]

still lgtm. thanks for uploading the fix patch separately

[commit-bot: I haz the power, 2017-05-17 16:51:22]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1495035478667080,
"parent_rev": "88768594c337f30f19c9b7ea2bd2d7d8820067a4", "commit_rev":
"512e6cd623a2039889c13d04759dd6714c08f663"}

[commit-bot: I haz the power, 2017-05-17 16:51:39]

Description was changed from

==========
This is reland of crrev.com/2884623002.

Added test uncovered a stack-use-after-scope issue in
AshTouchExplorationManager. Patch #2 fixes the issue.

Refactor backdrop that is currently used in the maximized mode.

The maximized mode creates a backdrop window so that a user will not see the
content of windows behind the top window,
in case it doesn't cover the entire window. (can happen if the maximize size is
specified for example)
This CL generalizes the backdrop code used in maximize mode as to create the
backdrop in the following scenarios:

1) Has a aura::client::kHasBackdrop property = true.
2) BackdropDelegate::HasBackdrop(aura::Window* window) returns true.
3) Active ARC window when the spoken feedback is enabled.

* Added delegate to check if the window should have a backdrop.
  Maximized mode always puts a backdrop.

* Added kHasBackdrop property for a window that needs a backdrop even in
clamshell.

* Move the accessibility feature implemented in exo's backbround. This
  is useful and should be there even for non-arc/exo case.

TBR=jamescook@chromium.org,reveman@chromium.org,sky@chromium.org
BUG=721646
TEST=coverted by unit tests

Review-Url: https://codereview.chromium.org/2884623002
Cr-Commit-Position: refs/heads/master@{#472401}
Committed:
https://chromium.googlesource.com/chromium/src/+/04936c54ed2396ae54cd824e24f1...

patch from issue 2884623002 at patchset 220001
(http://crrev.com/2884623002#ps220001)
==========

to

==========
This is reland of crrev.com/2884623002.

Added test uncovered a stack-use-after-scope issue in
AshTouchExplorationManager. Patch #2 fixes the issue.

Refactor backdrop that is currently used in the maximized mode.

The maximized mode creates a backdrop window so that a user will not see the
content of windows behind the top window,
in case it doesn't cover the entire window. (can happen if the maximize size is
specified for example)
This CL generalizes the backdrop code used in maximize mode as to create the
backdrop in the following scenarios:

1) Has a aura::client::kHasBackdrop property = true.
2) BackdropDelegate::HasBackdrop(aura::Window* window) returns true.
3) Active ARC window when the spoken feedback is enabled.

* Added delegate to check if the window should have a backdrop.
  Maximized mode always puts a backdrop.

* Added kHasBackdrop property for a window that needs a backdrop even in
clamshell.

* Move the accessibility feature implemented in exo's backbround. This
  is useful and should be there even for non-arc/exo case.

TBR=jamescook@chromium.org,reveman@chromium.org,sky@chromium.org
BUG=721646
TEST=coverted by unit tests

Review-Url: https://codereview.chromium.org/2884623002
Cr-Commit-Position: refs/heads/master@{#472401}
Committed:
https://chromium.googlesource.com/chromium/src/+/04936c54ed2396ae54cd824e24f1...

patch from issue 2884623002 at patchset 220001
(http://crrev.com/2884623002#ps220001)

Review-Url: https://codereview.chromium.org/2890733005
Cr-Commit-Position: refs/heads/master@{#472479}
Committed:
https://chromium.googlesource.com/chromium/src/+/512e6cd623a2039889c13d04759d...
==========

[commit-bot: I haz the power, 2017-05-17 16:51:40]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/512e6cd623a2039889c13d04759d...