The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/19bbb297811277de84ab541d81a60941a52e82e4

commit 19bbb297811277de84ab541d81a60941a52e82e4
Author: Ryan Landay <rlanday@chromium.org>
Date: Tue Jun 05 20:12:08 2018

Don't focus on previous tab in Android horizontal tab switcher

The new Android horizontal tab switcher currently focuses on the previous tab
when it's opened. We implemented this behavior because we thought the most
common action in the tab switcher is to switch to an earlier tab. However, user
metrics suggest that it's actually more common to switch to a later tab,
the most common action is actually to close the current tab. Additionally, we
received qualitative user feedback that this behavior feels annoying.

This CL removes this behavior so the horizontal tab switcher will now focus on
the current tab.

Bug: 831359, 849480 
Change-Id: Id77c422f51005b39a135a6682c75b3a7ab3dce24
Reviewed-on: https://chromium-review.googlesource.com/1085632
Commit-Queue: Ryan Landay <rlanday@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564635}
[modify] https://crrev.com/19bbb297811277de84ab541d81a60941a52e82e4/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/NonOverlappingStack.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/556a88c020d021a2e81e0953f4c87de7ee40159d

commit 556a88c020d021a2e81e0953f4c87de7ee40159d
Author: Ryan Landay <rlanday@chromium.org>
Date: Tue Jun 05 20:18:38 2018

Don't focus on previous tab in Android horizontal tab switcher

The new Android horizontal tab switcher currently focuses on the previous tab
when it's opened. We implemented this behavior because we thought the most
common action in the tab switcher is to switch to an earlier tab. However, user
metrics suggest that it's actually more common to switch to a later tab,
the most common action is actually to close the current tab. Additionally, we
received qualitative user feedback that this behavior feels annoying.

This CL removes this behavior so the horizontal tab switcher will now focus on
the current tab.

Bug: 831359, 849480 
Change-Id: Id77c422f51005b39a135a6682c75b3a7ab3dce24
Reviewed-on: https://chromium-review.googlesource.com/1085632
Commit-Queue: Ryan Landay <rlanday@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#564635}(cherry picked from commit 19bbb297811277de84ab541d81a60941a52e82e4)
Reviewed-on: https://chromium-review.googlesource.com/1087612
Reviewed-by: Ryan Landay <rlanday@chromium.org>
Cr-Commit-Position: refs/branch-heads/3440@{#191}
Cr-Branched-From: 010ddcfda246975d194964ccf20038ebbdec6084-refs/heads/master@{#561733}
[modify] https://crrev.com/556a88c020d021a2e81e0953f4c87de7ee40159d/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/NonOverlappingStack.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2a20c1c6458fac7eb0947fa908b1a9ae48198269

commit 2a20c1c6458fac7eb0947fa908b1a9ae48198269
Author: Ryan Landay <rlanday@chromium.org>
Date: Thu Jun 07 19:09:35 2018

Fix swiping down from toolbar to show current tab in new Android tab switcher

We previously had a behavior in the new Android horizontal tab switcher where
opening the tab switcher would show the previous tab instead of the current one.
I previously landed a CL to remove this behavior, but swiping down from the
toolbar is still showing the previous tab. It turns out there's a totally
separate piece of pre-existing logic that, together with the scroll snapping,
is actually causing swiping down from the toolbar to still go to the previous
tab. We of course did not notice this prior to removing the "show previous tab"
behavior.

This CL fixes this pre-existing logic to not show the previous tab.

Bug:  849480 ,831359
Change-Id: I0b89f87e536c5d4938638fbd6ac7fabde568e772
Reviewed-on: https://chromium-review.googlesource.com/1091230
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Ryan Landay <rlanday@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565372}
[modify] https://crrev.com/2a20c1c6458fac7eb0947fa908b1a9ae48198269/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/Stack.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c05f529ed48226b974a685edae03fb5c2c1dbb61

commit c05f529ed48226b974a685edae03fb5c2c1dbb61
Author: Ryan Landay <rlanday@chromium.org>
Date: Thu Jun 07 22:02:02 2018

Fix swiping down from toolbar to show current tab in new Android tab switcher

We previously had a behavior in the new Android horizontal tab switcher where
opening the tab switcher would show the previous tab instead of the current one.
I previously landed a CL to remove this behavior, but swiping down from the
toolbar is still showing the previous tab. It turns out there's a totally
separate piece of pre-existing logic that, together with the scroll snapping,
is actually causing swiping down from the toolbar to still go to the previous
tab. We of course did not notice this prior to removing the "show previous tab"
behavior.

This CL fixes this pre-existing logic to not show the previous tab.

Bug:  849480 ,831359
Change-Id: I0b89f87e536c5d4938638fbd6ac7fabde568e772
Reviewed-on: https://chromium-review.googlesource.com/1091230
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Ryan Landay <rlanday@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#565372}(cherry picked from commit 2a20c1c6458fac7eb0947fa908b1a9ae48198269)
Reviewed-on: https://chromium-review.googlesource.com/1091890
Reviewed-by: Ryan Landay <rlanday@chromium.org>
Cr-Commit-Position: refs/branch-heads/3440@{#250}
Cr-Branched-From: 010ddcfda246975d194964ccf20038ebbdec6084-refs/heads/master@{#561733}
[modify] https://crrev.com/c05f529ed48226b974a685edae03fb5c2c1dbb61/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/Stack.java

Verified that when opening the new horizontal tab switcher focuses on current tab instead of the previous tab.

Device: HTC 10/NRD90M
Build: 68.0.3440.23