[ash-md] Fixed ShelfBackgroundAnimator to not snap target values when being preempted.

[ash-md] Fixed ShelfBackgroundAnimator to not snap target values when being preempted.

Snapping to the target values was causing the shelf to flicker when dragging a
window while in OVERLAP mode. And on some platforms this contributed to the
shelf incorrectly being painted as DEFAULT mode.

BUG=695901
Review-Url: https://codereview.chromium.org/2749123003
Cr-Commit-Position: refs/heads/master@{#456892}
(cherry picked from commit 27dd2542a15215360c4f4fc8eeca9d72780d5167)

Review-Url: https://codereview.chromium.org/2768933003 .
Cr-Commit-Position: refs/branch-heads/3029@{#391}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/3af2743961f2dd4424ec6f802d832e0b193d6556

[bruthig, 2017-03-23 19:00:37]

Description was changed from

==========
[ash-md] Fixed ShelfBackgroundAnimator to not snap target values when being
preempted.

Snapping to the target values was causing the shelf to flicker when dragging a
window while in OVERLAP mode. And on some platforms this contributed to the
shelf incorrectly being painted as DEFAULT mode.

BUG=695901

Review-Url: https://codereview.chromium.org/2749123003
Cr-Commit-Position: refs/heads/master@{#456892}
(cherry picked from commit 27dd2542a15215360c4f4fc8eeca9d72780d5167)
==========

to

==========
[ash-md] Fixed ShelfBackgroundAnimator to not snap target values when being
preempted.

Snapping to the target values was causing the shelf to flicker when dragging a
window while in OVERLAP mode. And on some platforms this contributed to the
shelf incorrectly being painted as DEFAULT mode.

BUG=695901

Review-Url: https://codereview.chromium.org/2749123003
Cr-Commit-Position: refs/heads/master@{#456892}
(cherry picked from commit 27dd2542a15215360c4f4fc8eeca9d72780d5167)

Review-Url: https://codereview.chromium.org/2768933003 .
Cr-Commit-Position: refs/branch-heads/3029@{#391}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/3af2743961f2dd4424ec6f802d83...
==========

[bruthig, 2017-03-23 19:00:38]

Committed patchset #1 (id:1) manually as
3af2743961f2dd4424ec6f802d832e0b193d6556.