Replace uses of SkFixed for HarfBuzz conversions.

ui/gfx/skia_util.cc

Index: ui/gfx/skia_util.cc
diff --git a/ui/gfx/skia_util.cc b/ui/gfx/skia_util.cc
index c1e6c184ce17a257a08669dfd745636eb698f563..a971c9f22ecbe483a13e07a509fd13bca8aa469d 100644
--- a/ui/gfx/skia_util.cc
+++ b/ui/gfx/skia_util.cc
@@ -7,6 +7,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "base/numerics/safe_conversions.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColorFilter.h"
 #include "third_party/skia/include/core/SkColorPriv.h"
@@ -226,4 +227,21 @@ void QuadFToSkPoints(const gfx::QuadF& quad, SkPoint points[4]) {
   points[3] = PointFToSkPoint(quad.p4());
 }
 
+// We treat HarfBuzz ints as 16.16 fixed-point.
+static const int kHbUnit1 = 1 << 16;
+
+int SkiaScalarToHarfBuzzUnits(SkScalar value) {
+  return base::saturated_cast<int>(value * kHbUnit1);
+}
+
+SkScalar HarfBuzzUnitsToSkiaScalar(int value) {
+  static const SkScalar kSkToHbRatio = SK_Scalar1 / kHbUnit1;
+  return kSkToHbRatio * value;
+}
+
+float HarfBuzzUnitsToFloat(int value) {
+  static const float kFloatToHbRatio = 1.0f / kHbUnit1;
+  return kFloatToHbRatio * value;
+}
+
 }  // namespace gfx