Refactor SkGrFontScaler and SkGrFontKey into non-virtual versions.

src/gpu/GrTextStrike.cpp

Index: src/gpu/GrTextStrike.cpp
diff --git a/src/gpu/GrTextStrike.cpp b/src/gpu/GrTextStrike.cpp
index a9405ca8527c28a1042625b6542a99ebd744f7ad..b290d6c2a37cdf4a5a31ead724f24f639d1ff059 100644
--- a/src/gpu/GrTextStrike.cpp
+++ b/src/gpu/GrTextStrike.cpp
@@ -220,7 +220,7 @@ void GrFontCache::dump() const {
     atlas and a position within that texture.
  */
 
-GrTextStrike::GrTextStrike(GrFontCache* cache, const GrKey* key,
+GrTextStrike::GrTextStrike(GrFontCache* cache, const GrFontDescKey* key,
                            GrMaskFormat format,
                            GrAtlas* atlas) : fPool(64) {
     fFontScalerKey = key;