Bug 1479450: Convert GetStringValue to use Servo. r=xidorn

And remove gPropertyTable / kCSSRawProperties while at it.

Differential Revision: https://phabricator.services.mozilla.com/D2516

MozReview-Commit-ID: 8U87BcBkrJF

dom/animation/KeyframeEffect.cpp

@@ -818,7 +818,7 @@ void
 DumpAnimationProperties(nsTArray<AnimationProperty>& aAnimationProperties)
 {
   for (auto& p : aAnimationProperties) {
-    printf("%s\n", nsCSSProps::GetStringValue(p.mProperty).get());
+    printf("%s\n", nsCString(nsCSSProps::GetStringValue(p.mProperty)).get());
     for (auto& s : p.mSegments) {
       nsString fromValue, toValue;
       s.mFromValue.SerializeSpecifiedValue(p.mProperty, fromValue);