22105831: Application windows move erratically with two monitors

[openradar-mirror]

Description

Summary:
When dragging a window in OS X El Capitan, clicking on the window moves application frame unexpectedly and sometimes offscreen, where the window can no longer be manipulated or moved.

Steps to Reproduce:

1. Using a MacBook Pro with El Capitan installed, connect a Thunderbolt Display.
2. On the MacBook display, move a window to the center of the screen.
3. Click on the application frame.

Expected Results:
The window does not move until the mouse cursor drags the window to a new location.

Actual Results:
The window moves up and to the left. See attachment.

Product Version: 10.11 Beta (15A235d)
Created: 2015-08-01 22:03:32.463030
Originated: 2015-08-01T17:01:00
Open Radar Link: http://www.openradar.me/22105831