Version:  49.0.2623.110
OS: Ubuntu 12.04,14.04,Windows

What steps will reproduce the problem?

1.Launch Chrome -> Open any page(Ex:chrome://apps)and press F12 to open dev tools
2.Now drag the dev tools window to extreme Right(Please refer video)-> press F1 to open settings page ->Click on "Blackboxing"
3.Now click on "Add Pattern" Button and observe for "Pattern" Text box

Expected: "Pattern" Text box should be seen in  "Blackboxing" section
Actual: Instead "Pattern" Text box is not seen in "Blackboxing" section after dragging the devtools to R.H.S

This is Regression Issue broken in M-48
Manual good and Bad Builds:
Good Build: 48.0.2546.0 
Bad Build:  48.0.2547.0

Below is the Tool Bisect Info:

CHANGELOG URL:
https://chromium.googlesource.com/chromium/src/+log/b2f96a5eefb9ca66435bba93495b3cddcdcaa80d..a6210aabc0069535009389bd8e8cc76e1201b67a

Suspecting https://codereview.chromium.org/1422703003 from changelog

@dgozman: Please feel free to re-assign if its not related to your change

 

Deleted: Actual_TextBox.ogv 3.7 MB

Actual_TextBox.ogv 3.7 MB Download

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	Actual_TextBox.png 151 KB View Download

Deleted: Expected_TextBox.ogv 3.4 MB

Expected_TextBox.ogv 3.4 MB Download