Merge 112677 - Web Inspector: ScriptsNavigator scripts selection/focus polish.

Merge 112677 - Web Inspector: ScriptsNavigator scripts selection/focus polish.
https://bugs.webkit.org/show_bug.cgi?id=82732

Reviewed by Pavel Feldman.

Script could be selected by space in ScriptsNavigator now.
This patch also polishes focus behavior when using ScriptsNavigator.

* inspector/front-end/ScriptsNavigator.js:
(WebInspector.ScriptsNavigator.prototype._scriptSelected): Added focusSource param to give clients possibility to release focus.
(WebInspector.NavigatorScriptTreeElement.prototype.onspace): Added script selection on space pressed.
(WebInspector.NavigatorScriptTreeElement.prototype._onclick):
(WebInspector.NavigatorScriptTreeElement.prototype.onenter):
* inspector/front-end/ScriptsPanel.js: _hideNavigatorOverlay moved to the end of events processing to set focus correctly.
(WebInspector.ScriptsPanel.prototype._editorSelected):
(WebInspector.ScriptsPanel.prototype._fileSelected):
(WebInspector.ScriptsPanel.prototype._hideNavigatorOverlay):
* inspector/front-end/treeoutline.js:
(TreeOutline.prototype._treeKeyDown): onspace event added.

TBR=vsevik@chromium.org
BUG=121133
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=112684