some utils for rect and matrix

include/core/SkMatrix.h

Index: include/core/SkMatrix.h
diff --git a/include/core/SkMatrix.h b/include/core/SkMatrix.h
index da7838b78195c6a7d101a29399a49406270714e2..a272051067e7dabb511ac38d9ad01f07c206fd55 100644
--- a/include/core/SkMatrix.h
+++ b/include/core/SkMatrix.h
@@ -457,6 +457,12 @@ public:
         this->getMapXYProc()(*this, x, y, result);
     }
 
+    SkPoint mapXY(SkScalar x, SkScalar y) const {
+        SkPoint result;
+        this->getMapXYProc()(*this, x, y, &result);
+        return result;
+    }
+
     /** Apply this matrix to the array of vectors specified by src, and write
         the transformed vectors into the array of vectors specified by dst.
         This is similar to mapPoints, but ignores any translation in the matrix.
@@ -480,6 +486,17 @@ public:
         this->mapVectors(vecs, vecs, count);
     }
 
+    void mapVector(SkScalar dx, SkScalar dy, SkVector* result) const {
+        SkVector vec = { dx, dy };
+        this->mapVectors(result, &vec, 1);
+    }
+
+    SkVector mapVector(SkScalar dx, SkScalar dy) const {
+        SkVector vec = { dx, dy };
+        this->mapVectors(&vec, &vec, 1);
+        return vec;
+    }
+
     /** Apply this matrix to the src rectangle, and write the transformed
         rectangle into dst. This is accomplished by transforming the 4 corners
         of src, and then setting dst to the bounds of those points.