Bug 1514992 - Update annotation for webrender. r=lsalzman

Apparently we sometimes fall back to skia canvas with WebRender if ANGLE
fails to initialize. This makes the azureSkia condition true, but the
test still passes because of WebRender's magical properties. This patch
updates the annotation to reflect reality, so we don't get unexpected
passes.

Differential Revision: https://phabricator.services.mozilla.com/D21012

--HG--
extra : moz-landing-system : lando

layout/reftests/image-element/reftest.list

@@ -5,7 +5,7 @@ random == bug-364968.html bug-364968-ref.html
 == mozsetimageelement-02.html about:blank
 == image-outside-document-invalidate.html about:blank
 == canvas-outside-document-invalidate-01.html about:blank
-fails-if(azureSkia) fails-if(cocoaWidget) == canvas-outside-document-invalidate-02.html about:blank # See bug 666800
+fails-if(azureSkia&&!(webrender&&winWidget)) fails-if(cocoaWidget) == canvas-outside-document-invalidate-02.html about:blank # See bug 666800
 #fails with Skia due to Skia bug http://code.google.com/p/skia/issues/detail?id=568
 fuzzy-if(webrender&&!gtkWidget,117-129,47-54) == element-paint-simple.html element-paint-simple-ref.html
 == element-paint-repeated.html element-paint-repeated-ref.html