Web Inspector: Flame Chart. Provide Overview pane for better user expirience.
https://bugs.webkit.org/show_bug.cgi?id=112496

Reviewed by Yury Semikhatsky.

This patch implements basic part of Overview Pane in FlameChart.
The idea of the patch is to move everything into chart-container element.
And put OverviewGrid into new overview-container element.

Drive by change: fix the layout of the flame chart elements.
Drive by change: fix the drag window & drag resizer mechanics
for the case when the parent element has zero offsetLeft.

* inspector/front-end/FlameChart.js:
(WebInspector.FlameChart):
(WebInspector.FlameChart.OverviewCalculator):
(WebInspector.FlameChart.OverviewCalculator.prototype._updateBoundaries):
(WebInspector.FlameChart.OverviewCalculator.prototype.computePosition):
(WebInspector.FlameChart.OverviewCalculator.prototype.formatTime):
(WebInspector.FlameChart.OverviewCalculator.prototype.maximumBoundary):
(WebInspector.FlameChart.OverviewCalculator.prototype.minimumBoundary):
(WebInspector.FlameChart.OverviewCalculator.prototype.boundarySpan):
(WebInspector.FlameChart.prototype._onWindowChanged):
(WebInspector.FlameChart.prototype._adjustXScale):
(WebInspector.FlameChart.prototype.update):
* inspector/front-end/OverviewGrid.js:
(WebInspector.OverviewGrid.Window):
(WebInspector.OverviewGrid.Window.prototype._resizerElementStartDragging):
(WebInspector.OverviewGrid.Window.prototype._leftResizeElementDragging):
(WebInspector.OverviewGrid.Window.prototype._rightResizeElementDragging):
(WebInspector.OverviewGrid.Window.prototype._startWindowSelectorDragging):
(WebInspector.OverviewGrid.Window.prototype._windowSelectorDragging):
(WebInspector.OverviewGrid.Window.prototype._endWindowSelectorDragging):
(WebInspector.OverviewGrid.Window.prototype._setWindowPosition):
(WebInspector.OverviewGrid.Window.prototype._onMouseWheel):
(WebInspector.OverviewGrid.WindowSelector):
* inspector/front-end/TimelineOverviewPane.js:
* inspector/front-end/flameChart.css:
(.chart-container .item-anchor):
(.overview-container):
(.chart-container):
(#flame-chart-overview-grid .resources-dividers-label-bar):
* inspector/front-end/inspectorCommon.css:
(.resources-divider-label):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@146354 268f45cc-cd09-0410-ab3c-d52691b4dbfc