Disable the deprecated Alt+Shift for NEXT_IME

Disable the deprecated Alt+Shift for NEXT_IME

Due to its many conflicts, we decided to remove it for M-53. We will
keep the notification so as not to confuse users.

R=oshima@chromium.org
BUG=612990, 593633
TEST=ash_unittests --gtest_filter=DeprecatedAcceleratorTester.*
TEST=ash_unittests --gtest_filter=AcceleratorControllerTest.*

Committed: https://crrev.com/25174475a4ad63208a3dfc0755b4ced719ac2dfd
Cr-Commit-Position: refs/heads/master@{#400245}

[afakhry, 2016-06-15 20:32:59]

Patchset #1 (id:1) has been deleted

[afakhry, 2016-06-15 20:37:32]

Patchset #1 (id:20001) has been deleted

[afakhry, 2016-06-15 20:38:40]

Oshima, please review. Thanks!

[oshima, 2016-06-15 21:13:25]

https://codereview.chromium.org/2068333002/diff/40001/ash/accelerators/accele...
File ash/accelerators/accelerator_controller.cc (right):

https://codereview.chromium.org/2068333002/diff/40001/ash/accelerators/accele...
ash/accelerators/accelerator_controller.cc:308: // Non-chromeos platforms still
use the old NEXT_IME shortcuts.
why we need this? ash is chromeos only and win_ash is for testing purpose only.

[afakhry, 2016-06-16 18:40:49]

https://codereview.chromium.org/2068333002/diff/40001/ash/accelerators/accele...
File ash/accelerators/accelerator_controller.cc (right):

https://codereview.chromium.org/2068333002/diff/40001/ash/accelerators/accele...
ash/accelerators/accelerator_controller.cc:308: // Non-chromeos platforms still
use the old NEXT_IME shortcuts.
On 2016/06/15 21:13:25, oshima wrote:
> why we need this? ash is chromeos only and win_ash is for testing purpose
only.

Removed them entirely. 

Also, since Alt+Shift is triggered on key release, we need to avoid showing the
Deprecation notification for the wrong shortcuts. So, I did the following:
- Added NEXT/PREVIOUS_IME to non-repeatable accelerators.
- Added a function ShouldShowDeprecatedNextImeNotification() which checks for
the previous key being either Alt or Shift.

[oshima, 2016-06-16 19:07:11]

lgtm

[afakhry, 2016-06-16 19:20:04]

The CQ bit was checked by afakhry@chromium.org

[commit-bot: I haz the power, 2016-06-16 19:20:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2068333002/60001

[commit-bot: I haz the power, 2016-06-16 20:14:56]

Committed patchset #2 (id:60001)

[commit-bot: I haz the power, 2016-06-16 20:16:40]

Description was changed from

==========
Disable the deprecated Alt+Shift for NEXT_IME

Due to its many conflicts, we decided to remove it for M-53. We will
keep the notification so as not to confuse users.

R=oshima@chromium.org
BUG=612990,593633
TEST=ash_unittests --gtest_filter=DeprecatedAcceleratorTester.*
TEST=ash_unittests --gtest_filter=AcceleratorControllerTest.*
==========

to

==========
Disable the deprecated Alt+Shift for NEXT_IME

Due to its many conflicts, we decided to remove it for M-53. We will
keep the notification so as not to confuse users.

R=oshima@chromium.org
BUG=612990,593633
TEST=ash_unittests --gtest_filter=DeprecatedAcceleratorTester.*
TEST=ash_unittests --gtest_filter=AcceleratorControllerTest.*

Committed: https://crrev.com/25174475a4ad63208a3dfc0755b4ced719ac2dfd
Cr-Commit-Position: refs/heads/master@{#400245}
==========

[commit-bot: I haz the power, 2016-06-16 20:16:41]

Patchset 2 (id:??) landed as
https://crrev.com/25174475a4ad63208a3dfc0755b4ced719ac2dfd
Cr-Commit-Position: refs/heads/master@{#400245}