Add strikeout font metrics.

This also updates create_test_font so that it can be built, compiles,
and uses SkFontStyle instead of SkTypeface::Style.

BUG=b/63669723

Change-Id: I6eb0f851853f4721cf8e5052255b5b6750c3257f
Reviewed-on: https://skia-review.googlesource.com/24740
Reviewed-by: Cary Clark <caryclark@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/src/ports/SkFontHost_mac.cpp b/src/ports/SkFontHost_mac.cpp
index 92334cb..9456f03 100644
--- a/src/ports/SkFontHost_mac.cpp
+++ b/src/ports/SkFontHost_mac.cpp
@@ -1325,6 +1325,7 @@
     metrics->fUnderlineThickness = CGToScalar( CTFontGetUnderlineThickness(fCTFont.get()));
     metrics->fUnderlinePosition = -CGToScalar( CTFontGetUnderlinePosition(fCTFont.get()));
 
+    metrics->fFlags = 0;
     metrics->fFlags |= SkPaint::FontMetrics::kUnderlineThicknessIsValid_Flag;
     metrics->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;