[Merge] lp:~ahayzen/webbrowser-app/dnd-tabs-001 into lp:webbrowser-app

[Bill Filler]

previously was testing with unity7, and could drag a tab into it's own new window or drag into another existing browser window. this all functioned well.

On unity8, I encountered the following problems, guessing they are limitations with unity/mir
1) when trying to drag a tab into a new window it actually works but leaves an additional shadow window with pixelated display. so if you start with one window and drag out you are left with 3 windows.
2) cannot seem to drag out of one window and drop in another. I see an icon with circle with line through it on the drop target.
You should probably file qtmir bugs on these
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https://code.launchpad.net/~ahayzen/webbrowser-app/dnd-tabs-001/+merge/307061
Your team Ubuntu Phablet Team is requested to review the proposed merge of lp:~ahayzen/webbrowser-app/dnd-tabs-001 into lp:webbrowser-app.