Web Inspector: TimelineManager should reuse empty recordings
https://bugs.webkit.org/show_bug.cgi?id=135749

Reviewed by Timothy Hatcher.

Check whether the recording is empty before creating a new one.

* UserInterface/Controllers/TimelineManager.js:
(WebInspector.TimelineManager.prototype._loadNewRecording):
* UserInterface/Models/TimelineRecording.js:
(WebInspector.TimelineRecording.prototype.isEmpty):
(WebInspector.TimelineRecording.prototype.unloaded):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@172375 268f45cc-cd09-0410-ab3c-d52691b4dbfc