Issue granularity?

[Jeanette Winzenburg]

While working on a memory leak for ChoiceBoxSelection  
(https://bugs.openjdk.java.net/browse/JDK-8241455) I wrote a test  
covering the same issue in other controls with selection- and  
focusModels (the latter if available). Turned out it fails for

- TreeView selection- and focusModel
- TreeTableView focusModel
- TabPane selectionModel

all register listeners (eventHandler in the case of TreeView) to  
properties of the control with strong references, the fix is similar:  
use weakListeners (if that's the outcome of fixing choiceBoxSelection)

How to procede? Options seem to be

- one issue/pull request per control
- bulk issue/pull request for the all similar (keeping the current for  
ChoiceBox as is)
- include all into the current issue/pull request for ChoiceBox
- other?