https://bugs.webkit.org/show_bug.cgi?id=120384

Reviewed by Timothy Hatcher.

The Reload icon is duplicated just to provide different fill colors.
Convert from using <img> to an <svg> document for this image, and style
it with CSS. This also makes it trivial to add an :active state.

* UserInterface/ImageUtilities.js:
(.invokeCallbackWithDocument):
(.imageLoad):
(.imageError):
(wrappedSVGDocument):
Helpers for downloading and in memory caching SVG images.

* UserInterface/Images/Reload.svg:
* UserInterface/Images/ReloadSelected.svg: Removed.
Updated Reload image better matches the original design (slightly
larger). And the duplicate image can be removed.

* UserInterface/ResourceTreeElement.css:
(.item.resource > .status > .reload-button):
(.item.resource > .status > .reload-button > svg *):
(.item.resource.selected > .status > .reload-button > svg *):
(.item.resource.selected > .status > .reload-button:active > svg *):
Different styles, including a new :active style.

* UserInterface/ResourceTreeElement.js:
(WebInspector.ResourceTreeElement.prototype._updateStatusWithMainFrameButtons):
(WebInspector.ResourceTreeElement.prototype._updateStatus):
Handle updating the main frame's state asynchronously since loading the SVG
image document is asynchronous.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154777 268f45cc-cd09-0410-ab3c-d52691b4dbfc