Editing a gadget while in canvas mode causes the gadget iframe to be clipped

Steps to reproduce:

1. Create an empty dashboard and add an "Average Age Chart" gadget.
2. Set it to use a filter/project with lots of issues such that Days Previously = N returns <5 results, while Days Previously = M returns >25 results.
3. Set Days Previously to N and save.
4. Click the gadget's maximise button to put it into canvas mode.
5. Use the dropdown menu to edit the gadget's settings.
6. Set Days Previously to M and save.

Result: The dashboard is not resized to accommodate the greater number of issues in the gadget, so the iframe appears clipped. (See screenshot.)

Note: Depending on how quickly the ajax response completes, this may intermittently work as expected. Try using Charles (HTTP proxy) or a browser other than Chrome to ensure repeatable results.