Could reproduce this on the latest M-52(52.0.2726.0) on Linux Ubuntu 14.04 and Windows-7. Mac latest M-52 is not yet available. Will update the behavior once it's there.

CHANGELOG URL:
 https://chromium.googlesource.com/chromium/src/+log/07997eedaf5f406b931e8f3cfa837a039d0e1f0c..2ed9de59b70764210324c594634228ae882c75bd

Suspecting  https://codereview.chromium.org/1894383002 from changelog.

@karandeepb: Please confirm the issue and help in re-assigning if it is not related to your change.

Another issue is seen with same culprit as suspect.

Steps:
1.Click wrench menu and observe Underlines on some of the letters.[Ex: t in New tab,H in History,D in Downloads etc..]

Till 52.0.2725.0 dev only on using shortcut key[Alt+e] to show up wrench menu brings the issue but in 52.0.2726.0 dev by default underlines are seen and on using shortcut alt+e doesn't show up any underlines.

Have confirmed my CL is the cause. Will issue a fix soon. Thanks.

Just to update this bug, Issue is still observed on Windows 7 using chrome latest canary M52-52.0.2730.0.

 Issue 610592  has been merged into this issue.

CL - https://codereview.chromium.org/1963563002/

 Issue 611874  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8c6b2ee186d786623f0e4cb6d05c08c934c0ff9b

commit 8c6b2ee186d786623f0e4cb6d05c08c934c0ff9b
Author: karandeepb <karandeepb@chromium.org>
Date: Mon May 16 01:14:44 2016

Views: Change View::RequestFocus to respect keyboard accessibility.

This CL fixes some regressions introduced in http://crrev.com/1894383002/. These
regression are caused due to the change in View::RequestFocus() from
IsFocusable() to IsAccessibilityFocusable().

On a mouse click on a CustomButton, CustomButton::MousePressed() requests focus
on the button, if it has request_focus_on_press_ set to true. It turns out that
most button subclasses, do not explicitly set request_focus_on_press_ to false,
which has a default value of true. These custom buttons which are accessibility
focusable, can now gain focus on a mouse press, hence the bug.

This CL changes View::RequestFocus to use IsFocusable when keyboard
accessibility is off (i.e on Non-Mac platforms), hence fixing bugs  609701 ,
610186, 610235, 610740, 610802, 610664. This is how View::RequestFocus behaved
before crrev.com/1894383002 on Non-Mac platforms. Also, on Mac, since
View::RequestFocus now respects keyboard accessibility,  bug 611280  is also
fixed.

BUG= 609701 ,  610186 ,  610235 ,  610740 ,  610802 ,  610664 ,  564912 ,  611280 

Review-Url: https://codereview.chromium.org/1973073003
Cr-Commit-Position: refs/heads/master@{#393781}

[modify] https://crrev.com/8c6b2ee186d786623f0e4cb6d05c08c934c0ff9b/chrome/browser/ui/views/tabs/tab_unittest.cc
[modify] https://crrev.com/8c6b2ee186d786623f0e4cb6d05c08c934c0ff9b/ui/views/focus/focus_manager.cc
[modify] https://crrev.com/8c6b2ee186d786623f0e4cb6d05c08c934c0ff9b/ui/views/focus/focus_manager_unittest.cc
[modify] https://crrev.com/8c6b2ee186d786623f0e4cb6d05c08c934c0ff9b/ui/views/view.cc

ChromeOS 8337.0.0, 52.0.2739.0

[Auto-generated comment by a script] We noticed that this issue is targeted for M-52; it appears the fix may have landed after branch point, meaning a merge might be required. Please confirm if a merge is required here - if so add Merge-Request-52 label, otherwise remove Merge-TBD label. Thanks.

[Bulk edit]

Our blockerbot script was offline; it was recently brought back online, and thus labeled many old issues (including this one) erroneously.  Removing Merge-TBD label since all milestones for this issue are already completed; no further work should be done.