Strange behavior when resizing profile plots

**OS:** Windows 10 x64
**Version:**

**Description**
When resizing profile plots on the bottom right corner without previously activating the window, the targeted window size is often not reach during the repainting of the plot. It often happens, that the plot snaps back to its original size, or, when moving back and forth between a larger and a smaller size, snaps back to the larger size.

Here is a GIF showcasing the issue:

**Steps for Reproduction**
1. Start ImageJ
2. Click on File -> Open Samples -> CT (16-bit DICOM)
3. Select the Line Tool and draw an arbitrary horizonal line somewhere in the image
4. Press Ctrl-K or manually select Analyze -> Plot Profile
5. Without clicking in the title bar of the profile plot window, go to the bottom right corner until the mouse pointer is changed to the diagonal resizing icon. Click and hold the left mouse button.
6. Play around with different window sizes. Depending on the current requested new window size, the repainting of the plot will not match the requested size. Sometimes the plot will jump back to a larger size even though a smaller size was requested, sometimes the opposite occurs.

Reproduce the issue in ImageJ using File -> Open Samples -> CT (16-bit DICOM), the Line Tool, and Analyze -> Plot Profile, then resize the plot without activating its title bar. Trace the profile plot repaint and resize behavior; done means the plot consistently reaches and stays at the requested window size.

Written by the indexing model from the issue text.