Clean up and refactor TimelineDecorations into TimelineRuler.

https://bugs.webkit.org/show_bug.cgi?id=125709

Reviewed by Joseph Pecoraro.

* UserInterface/Main.html:
* UserInterface/OverviewTimelineView.css:
(.timeline-view.overview > .timeline-ruler):
(.timeline-view.overview > .timeline-ruler > .header):
(.timeline-view.overview > .timeline-ruler > .event-markers):
Updated class names and border sides.

* UserInterface/OverviewTimelineView.js:
(WebInspector.OverviewTimelineView):
(WebInspector.OverviewTimelineView.prototype.updateLayout):
Call updateLayout on the TimelineRuler.

* UserInterface/TimelineRuler.css: Renamed from Source/WebInspectorUI/UserInterface/TimelineDecorations.css.
(.timeline-ruler):
(.timeline-ruler > .header):
(.timeline-ruler > .header > .divider):
(.timeline-ruler > .header > .divider > .label):
(.timeline-ruler > .event-markers):
(.timeline-ruler > .event-markers > .event-marker-tooltip):
(.timeline-ruler > .event-markers > .event-marker):
(.timeline-ruler > .event-markers > .event-marker.load-event):
(.timeline-ruler > .event-markers > .event-marker.dom-content-event):
(.timeline-ruler > .event-markers > .event-marker.timestamp):
Updated class names and border sides.

* UserInterface/TimelineRuler.js: Renamed from Source/WebInspectorUI/UserInterface/TimelineDecorations.js.
(WebInspector.TimelineRuler):
(WebInspector.TimelineRuler.prototype.get element):
(WebInspector.TimelineRuler.prototype.get headerElement):
(WebInspector.TimelineRuler.prototype.get allowsClippedLabels):
(WebInspector.TimelineRuler.prototype.set allowsClippedLabels):
(WebInspector.TimelineRuler.prototype.get zeroTime):
(WebInspector.TimelineRuler.prototype.set zeroTime):
(WebInspector.TimelineRuler.prototype.get startTime):
(WebInspector.TimelineRuler.prototype.set startTime):
(WebInspector.TimelineRuler.prototype.get duration):
(WebInspector.TimelineRuler.prototype.set duration):
(WebInspector.TimelineRuler.prototype.get endTime):
(WebInspector.TimelineRuler.prototype.set endTime):
(WebInspector.TimelineRuler.prototype.get secondsPerPixel):
(WebInspector.TimelineRuler.prototype.set secondsPerPixel):
(WebInspector.TimelineRuler.prototype.updateLayout.removeDividerAndSelectNext):
(WebInspector.TimelineRuler.prototype.updateLayout):
(WebInspector.TimelineRuler.prototype._needsLayout):
(WebInspector.TimelineRuler.prototype._recalculate):
Refactor so the times are stored on TimelineRuler and not passed in each time an update is needed.
Support dividers that don't always start at the zero position, allowing a sliding time ruler.
Support for a non-pinned ruler where the end time is not fixed and the scale is specified in
seconds-per-pixel.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162407 268f45cc-cd09-0410-ab3c-d52691b4dbfc