create shared helper for strikecache and SkFont

Bug: skia:
Change-Id: Ie6ffca1f4e2fc41474eb30d27503b0b76631d077
Reviewed-on: https://skia-review.googlesource.com/c/171202
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Mike Reed <reed@google.com>
Reviewed-by: Herb Derby <herb@google.com>
diff --git a/src/core/SkStrikeCache.h b/src/core/SkStrikeCache.h
index c4584a5..df7f61e 100644
--- a/src/core/SkStrikeCache.h
+++ b/src/core/SkStrikeCache.h
@@ -134,6 +134,8 @@
 
     static ExclusiveStrikePtr FindOrCreateStrikeWithNoDeviceExclusive(const SkPaint& paint);
 
+    static ExclusiveStrikePtr FindOrCreateStrikeWithNoDeviceExclusive(const SkFont&);
+
     static std::unique_ptr<SkScalerContext> CreateScalerContext(
             const SkDescriptor&, const SkScalerContextEffects&, const SkTypeface&);