The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bba7e8ac988500dc87a1de6c4809628a9415a1c8

commit bba7e8ac988500dc87a1de6c4809628a9415a1c8
Author: dpapad <dpapad@chromium.org>
Date: Tue May 22 22:34:42 2018

WebUI MD Refresh: Apply new button style in various signin dialogs.

Bug:  843770 , 843348 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Ifb8517c90cecd569b6600b896329d713a96c82e7
Reviewed-on: https://chromium-review.googlesource.com/1068074
Reviewed-by: Scott Chen <scottchen@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560818}
[modify] https://crrev.com/bba7e8ac988500dc87a1de6c4809628a9415a1c8/chrome/browser/resources/signin/dice_sync_confirmation/sync_confirmation_app.html
[modify] https://crrev.com/bba7e8ac988500dc87a1de6c4809628a9415a1c8/chrome/browser/resources/signin/signin_email_confirmation/signin_email_confirmation.html
[modify] https://crrev.com/bba7e8ac988500dc87a1de6c4809628a9415a1c8/chrome/browser/resources/signin/signin_error/signin_error.html
[modify] https://crrev.com/bba7e8ac988500dc87a1de6c4809628a9415a1c8/chrome/browser/resources/signin/signin_shared_css.html
[modify] https://crrev.com/bba7e8ac988500dc87a1de6c4809628a9415a1c8/chrome/browser/resources/signin/sync_confirmation/sync_confirmation.html
[modify] https://crrev.com/bba7e8ac988500dc87a1de6c4809628a9415a1c8/ui/webui/resources/cr_elements/paper_button_style_css.html

Tested this issue on Mac OS 10.13.3 on the build without fix 68.0.3430.0 and on the latest Canary 68.0.3438.0 by following the below steps.
Unable to check and verify the issue on Windows 10 and Ubuntu 14.04 due to the  issue 845836  and  845789 .

1. Launched Chrome and in Chrome://flags, set the #top-chrome-md flag to refresh.
2. Signed into Chrome and the sync-confirmation screen is observed as in older builds.
3. unable to see any difference on the build with fix and without fix by following the above steps.

Attached are the screen shots for reference.

dpapad@ Request you to check and confirm if anything is missed from our end in checking the issue.
Also request you to confirm the fix on the latest Canary 68.0.3438.0 build.

Thanks..

Deleted: 843348-build without fix.png 140 KB

	843348-build without fix.png 140 KB View Download

Deleted: 843348-build-with fix.png 120 KB

	843348-build-with fix.png 120 KB View Download

> 3. unable to see any difference on the build with fix and without fix by following the above steps.

Look at the two buttons in the bottom. They look different, therefore this is verified.