Using the per-revision bisect providing the bisect results,
Good build: 59.0.3071.0 (Revision: 464641).
Bad build : 60.0.3072.0 (Revision: 464836).

You are probably looking for a change made after 464697 (known good), but no later than 464698 (first known bad).
CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/188c1056bbfb9c98eca691c12f5641d4204f6066..0f65d25a4097959d977dbb1077717323438240a6

@hugoh: Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to concern owner.

Thank You.

I cannot explain this one. dpapad@, can you? 

@yosin, let's revert my CL until we understand these regressions better? 

Assigning to yosin@ for reverting. I tried to revert but the original CL can't be rolled back cleanly at this point.

When the selection is hidden, context menu should use focused element as context (not the caret position). 

Minimal repro:

<input autofocus><a href="www"">link</a>
1. Hit tab key to go focus the link.
2. Shift+F10.
Expected: Context menu for <a>.
Actual: Context menu for <input>.

Here's a quick fix: https://codereview.chromium.org/2841093002

I could not reproduce on 60.0.3081.0.
Context menu is showed at link, e.g. "learn more"

Could you do bisect? I would like to know which CL fixed this issue.

Please ignore #c8. I could reproduce with 60.0.3081.0
Sorry for confusion.

 Issue 715905  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8549ed4eaf9d95db494bd7028bf17110b26b6918

commit 8549ed4eaf9d95db494bd7028bf17110b26b6918
Author: hugoh <hugoh@opera.com>
Date: Thu May 11 05:28:29 2017

Algorithm for deciding if a frame's selection should be hidden

Background:
Crrev.com/464698 introduced "hiding" of unfocused selections
in text controls. Hiding avoids clearing the selection upon change
of focus.

Problem:
Now we only hide selections inside text controls.
Selections within content-editable elements must also be hidden.

Solution:
Generalize previous work into an algorithm that, given current
DOM and its activeElement, determines whether a frame's selection
should be hidden.

See the algorithm in InHidden() for documentation and read its
unit tests in FrameSelectionTest.cpp.

BUG= 715059 ,  715889 

Review-Url: https://codereview.chromium.org/2841093002
Cr-Commit-Position: refs/heads/master@{#470822}

[modify] https://crrev.com/8549ed4eaf9d95db494bd7028bf17110b26b6918/third_party/WebKit/Source/core/editing/FrameSelection.cpp
[modify] https://crrev.com/8549ed4eaf9d95db494bd7028bf17110b26b6918/third_party/WebKit/Source/core/editing/FrameSelection.h
[modify] https://crrev.com/8549ed4eaf9d95db494bd7028bf17110b26b6918/third_party/WebKit/Source/core/editing/FrameSelectionTest.cpp
[modify] https://crrev.com/8549ed4eaf9d95db494bd7028bf17110b26b6918/third_party/WebKit/Source/core/editing/LayoutSelection.cpp
[modify] https://crrev.com/8549ed4eaf9d95db494bd7028bf17110b26b6918/third_party/WebKit/Source/core/editing/LayoutSelection.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ff7930cd4d17f38e69016d96024acadf8a008a4d

commit ff7930cd4d17f38e69016d96024acadf8a008a4d
Author: hugoh <hugoh@opera.com>
Date: Mon May 15 10:28:59 2017

Make context menu aware of hidden selection

When the frame's selection is hidden, the context menu should
use the focused element (not the selection) as context.

BUG= 715059 

Expected: Context menu for <a>.
Review-Url: https://codereview.chromium.org/2869713003
Cr-Commit-Position: refs/heads/master@{#471719}

[modify] https://crrev.com/ff7930cd4d17f38e69016d96024acadf8a008a4d/third_party/WebKit/LayoutTests/NeverFixTests
[add] https://crrev.com/ff7930cd4d17f38e69016d96024acadf8a008a4d/third_party/WebKit/LayoutTests/fast/events/contextmenu-follows-focus.html
[modify] https://crrev.com/ff7930cd4d17f38e69016d96024acadf8a008a4d/third_party/WebKit/Source/core/input/EventHandler.cpp