Mozart: Compute hits using 4x4 matrix.

mojo/skia/type_converters.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_SKIA_TYPE_CONVERTERS_H_
 #define MOJO_SKIA_TYPE_CONVERTERS_H_
 
 #include "mojo/services/geometry/interfaces/geometry.mojom.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkPoint.h"
 #include "third_party/skia/include/core/SkRRect.h"
 #include "third_party/skia/include/core/SkRect.h"
+#include "third_party/skia/include/utils/SkMatrix44.h"
 
 namespace mojo {
 
 template <>
 struct TypeConverter<SkIPoint, mojo::Point> {
   static SkIPoint Convert(const mojo::Point& input);
 };
 template <>
 struct TypeConverter<mojo::Point, SkIPoint> {
   static mojo::Point Convert(const SkIPoint& input);
@@ skipping 29 matching lines @@
 template <>
 struct TypeConverter<SkRRect, mojo::RRectF> {
   static SkRRect Convert(const mojo::RRectF& input);
 };
 template <>
 struct TypeConverter<mojo::RRectF, SkRRect> {
   static mojo::RRectF Convert(const SkRRect& input);
 };
 
 // Note: This transformation is lossy since Transform is 4x4 whereas
-// SkMatrix is only 3x3.
+// SkMatrix is only 3x3 so we drop the 3rd row and column.
 template <>
 struct TypeConverter<SkMatrix, mojo::TransformPtr> {
   static SkMatrix Convert(const mojo::TransformPtr& input);
 };
 template <>
 struct TypeConverter<mojo::TransformPtr, SkMatrix> {
   static mojo::TransformPtr Convert(const SkMatrix& input);
 };
 
+// Note: This transformation is lossless.
+template <>
+struct TypeConverter<SkMatrix44, mojo::TransformPtr> {
+  static SkMatrix44 Convert(const mojo::TransformPtr& input);
+};
+template <>
+struct TypeConverter<mojo::TransformPtr, SkMatrix44> {
+  static mojo::TransformPtr Convert(const SkMatrix44& input);
+};
+
 }  // namespace mojo
 
 #endif  // MOJO_SKIA_TYPE_CONVERTERS_H_