Fixes <http://webkit.org/b/31699>.

Fixes <http://webkit.org/b/31699>.
Web Inspector: Should Cache Values of InspectorController.platform() and port().

Reviewed by Tim Hatcher.

Refactor the Inspector to cache the value of InspectorController.platform
and InspectorController.port, because those need to call into C++, they are
being called more and more as we add platform specific keyboard shortcuts, and
they shouldn't change in the lifecycle of the Web Inspector.

* inspector/front-end/AbstractTimelinePanel.js:
(WebInspector.AbstractTimelinePanel.prototype._updateFilter):
* inspector/front-end/ConsoleView.js:
(WebInspector.ConsoleView.prototype._updateFilter):
* inspector/front-end/ElementsPanel.js:
(WebInspector.ElementsPanel.prototype.handleKeyEvent):
* inspector/front-end/ScriptsPanel.js:
(WebInspector.ScriptsPanel):
* inspector/front-end/SourceFrame.js:
(WebInspector.SourceFrame.prototype._loaded):
* inspector/front-end/inspector.js:
(WebInspector.get platform):
(WebInspector.get port):
(WebInspector.loaded):
(WebInspector.documentKeyDown):
(WebInspector.toolbarDragStart):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@51242 268f45cc-cd09-0410-ab3c-d52691b4dbfc