UserAgent: Mozilla/5.0 (X11; CrOS x86_64 8172.60.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36
Platform: 8172.60.0 (Official Build) stable-channel panther

Steps to reproduce the problem:
1. Dual monitors
2. Position shelf on left, and on right
3. Open Chrome Window and have it from top to bottom
4. Lock the computer (you will notice the shelf reposition to the bottom if you are carefully watching)
5. Unlock the computer
6. Window will no longer be top to bottom, but will have shortened the height of the shelf (the shelf will properly be on the left/right, only the window will be affected by the temporary movement of the shelf to the bottom during lock)

What is the expected behavior?
The shelf should not temporarily re-position itself. It should stay on the left/right, and not move to the bottom.

What went wrong?
I have dual monitors, and I have the shelf position on the left for one, and the right for the other. Every time I lock the screen when I step away from the computer, it will throw the shelf on the bottom a split second before it locks, so when I wake the computer back up, my windows are shortened by the amount of the shelf while it was on the bottom. The shelf position is correct upon waking, but any top to bottom windows (see screenshot) or full monitor windows are shortened or misplaced since the menu bar is actually being put on the bottom every lock. This was not the case prior to the third update on Stable 51. I do not know the exact number.

Did this work before? Yes Two versions prior to current build. It worked properly on Stable 51 upon release. I believe it worked on one subsequent update, and then the following update regressed. Current update did not fix this issue.

Chrome version: 51.0.2704.103  Channel: stable
OS Version: 8172.60.0
Flash Version: Shockwave Flash 22.0 r0

The behavior is identical to simply moving the shelf to the bottom. Windows will immediately resize to allow space on the bottom. When you manually move the shelf to the right/left, the windows will not resize (as it has been for years). However, what seems to be new, is when locking (Search+L), the shelf appears to be sent to the bottom automatically, causing the issue.