Of the two shown below, which is the preferred style--if any--for a combo control? (that allows you to type in it or click the button or arrow to show a drop-down with choices to select...in this case, in a tree). I have a preference, but want to coordinate with others.
The only difference being the appearance of the button to request the dropdown. Note: when the user hovers the cursor over the arrow in Style 2, it changes to this:
In addition to which style may be UX preferable, there is also the question of what is "more native". These were taken on Windows 7, so I'd like to also know what is native for this sort of control on that platform.
EDIT: I added an additional view of Style 2.