weidongg, I have an early version of keyboard focus of this: https://chromium-review.googlesource.com/c/557464/, it is not inline with the UX requirement yet.

Also

1. Remove the voice search icon.
2. Always left align the placeholder text.

IMHO, the search box text field should remain selectable/focusable as the old launcher. When the search box text field is focused in the old launcher, it makes an accessibility notification. 
Also, the mic button is possibly missing when speech recognition is disabled. It may not be a good initial focus, compared to the search box text field which always exists.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9

commit a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9
Author: Weidong Guo <weidongg@chromium.org>
Date: Fri Jul 21 23:02:42 2017

Update start page view tab key focus

Changes:
1. Change the focus behavior triggered by tab key in start page view.
Focus should move cyclically like this: search box text field ->
suggestion apps -> expand arrow view -> search box text field.
2. Add unit test for this behavior.

BUG= 741015 
TEST=AppListViewFullscreenTest.StartPageTabFocusTest

Change-Id: I7467d94b4028ef24422f8236e615f66b195d1f84
Reviewed-on: https://chromium-review.googlesource.com/580498
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Yury Khmel <khmel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488780}
[modify] https://crrev.com/a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9/ui/app_list/views/app_list_view_unittest.cc
[modify] https://crrev.com/a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9/ui/app_list/views/contents_view.cc
[modify] https://crrev.com/a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9/ui/app_list/views/search_box_view.cc
[modify] https://crrev.com/a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9/ui/app_list/views/search_box_view.h
[modify] https://crrev.com/a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9/ui/app_list/views/start_page_view.cc
[modify] https://crrev.com/a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9/ui/app_list/views/start_page_view.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/88173e0dbe883b53382e05132fa9bad4fd3ca519

commit 88173e0dbe883b53382e05132fa9bad4fd3ca519
Author: Weidong Guo <weidongg@chromium.org>
Date: Sat Jul 29 00:51:42 2017

Update start page view tab key focus

Changes:
1. Change the focus behavior triggered by tab key in start page view.
Focus should move cyclically like this: search box text field ->
suggestion apps -> expand arrow view -> search box text field.
2. Add unit test for this behavior.

BUG= 741015 
TEST=AppListViewFullscreenTest.StartPageTabFocusTest
TBR=weidongg@chromium.org

(cherry picked from commit a4bb0a79d97dea6cd74e5c5272781aa9fd9300d9)

Change-Id: I7467d94b4028ef24422f8236e615f66b195d1f84
Reviewed-on: https://chromium-review.googlesource.com/580498
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Yury Khmel <khmel@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#488780}
Reviewed-on: https://chromium-review.googlesource.com/592687
Reviewed-by: Vadim Tryshev <vadimt@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#128}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
[modify] https://crrev.com/88173e0dbe883b53382e05132fa9bad4fd3ca519/ui/app_list/views/app_list_view_unittest.cc
[modify] https://crrev.com/88173e0dbe883b53382e05132fa9bad4fd3ca519/ui/app_list/views/contents_view.cc
[modify] https://crrev.com/88173e0dbe883b53382e05132fa9bad4fd3ca519/ui/app_list/views/search_box_view.cc
[modify] https://crrev.com/88173e0dbe883b53382e05132fa9bad4fd3ca519/ui/app_list/views/search_box_view.h
[modify] https://crrev.com/88173e0dbe883b53382e05132fa9bad4fd3ca519/ui/app_list/views/start_page_view.cc
[modify] https://crrev.com/88173e0dbe883b53382e05132fa9bad4fd3ca519/ui/app_list/views/start_page_view.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/deec7ef0e726c1806fa205078d36acea995029bb

commit deec7ef0e726c1806fa205078d36acea995029bb
Author: Weidong Guo <weidongg@chromium.org>
Date: Tue Aug 08 01:16:38 2017

cros: update start page view arrow key focus

Changes:
1. Make the left and right arrow keys behavior the same as shift+tab key
and tab key.
2. Implement the behavior of up and down arrow key.
3. Separate the key handling of start page view in fullscreen app list
into one single function for readability.
4. add unit tests for arrow key focus movement in start page view and
search box view.

Specs:
https://screenshot.googleplex.com/BszbVX5GHKa

BUG= 741015 
TEST=AppListViewFullscreenTest.*

Change-Id: If19371109a350f05d6a6cf8a78bc059f15905aa5
Reviewed-on: https://chromium-review.googlesource.com/604467
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Reviewed-by: Yury Khmel <khmel@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492488}
[modify] https://crrev.com/deec7ef0e726c1806fa205078d36acea995029bb/ui/app_list/views/app_list_view_unittest.cc
[modify] https://crrev.com/deec7ef0e726c1806fa205078d36acea995029bb/ui/app_list/views/contents_view.cc
[modify] https://crrev.com/deec7ef0e726c1806fa205078d36acea995029bb/ui/app_list/views/search_box_view.cc
[modify] https://crrev.com/deec7ef0e726c1806fa205078d36acea995029bb/ui/app_list/views/search_box_view.h
[modify] https://crrev.com/deec7ef0e726c1806fa205078d36acea995029bb/ui/app_list/views/search_box_view_unittest.cc
[modify] https://crrev.com/deec7ef0e726c1806fa205078d36acea995029bb/ui/app_list/views/start_page_view.cc
[modify] https://crrev.com/deec7ef0e726c1806fa205078d36acea995029bb/ui/app_list/views/start_page_view.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1a3dfce0a20ac5798758cd73c32468463b061f4d

commit 1a3dfce0a20ac5798758cd73c32468463b061f4d
Author: Maajid <maajid@chromium.org>
Date: Thu Aug 10 21:40:11 2017

cros: update start page view arrow key focus

Changes:
1. Make the left and right arrow keys behavior the same as shift+tab key
and tab key.
2. Implement the behavior of up and down arrow key.
3. Separate the key handling of start page view in fullscreen app list
into one single function for readability.
4. add unit tests for arrow key focus movement in start page view and
search box view.

Specs:
https://screenshot.googleplex.com/BszbVX5GHKa

BUG= 741015 
TEST=AppListViewFullscreenTest.*
TBR=weidongg@chromium.org

(cherry picked from commit deec7ef0e726c1806fa205078d36acea995029bb)

Change-Id: If19371109a350f05d6a6cf8a78bc059f15905aa5
Reviewed-on: https://chromium-review.googlesource.com/604467
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Reviewed-by: Yury Khmel <khmel@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#492488}
Reviewed-on: https://chromium-review.googlesource.com/611158
Reviewed-by: Vadim Tryshev <vadimt@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#464}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
[modify] https://crrev.com/1a3dfce0a20ac5798758cd73c32468463b061f4d/ui/app_list/views/app_list_view_unittest.cc
[modify] https://crrev.com/1a3dfce0a20ac5798758cd73c32468463b061f4d/ui/app_list/views/contents_view.cc
[modify] https://crrev.com/1a3dfce0a20ac5798758cd73c32468463b061f4d/ui/app_list/views/search_box_view.cc
[modify] https://crrev.com/1a3dfce0a20ac5798758cd73c32468463b061f4d/ui/app_list/views/search_box_view.h
[modify] https://crrev.com/1a3dfce0a20ac5798758cd73c32468463b061f4d/ui/app_list/views/search_box_view_unittest.cc
[modify] https://crrev.com/1a3dfce0a20ac5798758cd73c32468463b061f4d/ui/app_list/views/start_page_view.cc
[modify] https://crrev.com/1a3dfce0a20ac5798758cd73c32468463b061f4d/ui/app_list/views/start_page_view.h