Created attachment 260787 [details]
Smaller width dev tools
When the dev tools window has a small width, the tab close button replaces the tab icon, rather than being a new hard left aligned icon. This is counterintuitive as everywhere else in the OS X platform, a close button is always hard left, and it is harder to click. I've attached screenshots showing the different behaviour.
Created attachment 260788 [details]
Larger width devotees
This is by design. To have the tab icon (unlike Safari) the close box needs to replace the icon when there ins't room to show both.
Would it be possible to hide the icon or move it to the left instead then? The other thing I noticed is that because the tab names have different lengths, the close box is not even in a consistent spot for each tab.
Moving the icon would cause a visual change as you resize that would me a caring jump to the user. Since the close button is not used regularly and is only on hover, this was the best design we could come up with while keeping the icons in the tab.