speed up maprect for scale+trans case

bench/MatrixBench.cpp

Index: bench/MatrixBench.cpp
diff --git a/bench/MatrixBench.cpp b/bench/MatrixBench.cpp
index a185fec58953a12a068294e172aad3484ff5d791..53e72967313e2deebdfc72e602a9a7a631bb7f5b 100644
--- a/bench/MatrixBench.cpp
+++ b/bench/MatrixBench.cpp
@@ -297,3 +297,37 @@ DEF_BENCH( return new MapPointsMatrixBench("mappoints_identity", SkMatrix::I());
 DEF_BENCH( return new MapPointsMatrixBench("mappoints_trans", make_trans()); )
 DEF_BENCH( return new MapPointsMatrixBench("mappoints_scale", make_scale()); )
 DEF_BENCH( return new MapPointsMatrixBench("mappoints_affine", make_afine()); )
+
+///////////////////////////////////////////////////////////////////////////////
+
+class MapRectMatrixBench : public MatrixBench {
+    SkMatrix fM;
+    SkRect   fR;
+    bool     fScaleTrans;
+
+    enum { MEGA_LOOP = 1000 * 1000 };
+public:
+    MapRectMatrixBench(const char name[], bool scale_trans)
+        : MatrixBench(name), fScaleTrans(scale_trans)
+    {
+        fM.setScale(2, 3);
+        fM.postTranslate(1, 2);
+
+        fR.set(10, 10, 100, 200);
+    }
+
+    void performTest() override {
+        SkRect dst;
+        if (fScaleTrans) {
+            for (int i = 0; i < MEGA_LOOP; ++i) {
+                fM.mapRectScaleTranslate(&dst, fR);
+            }
+        } else {
+            for (int i = 0; i < MEGA_LOOP; ++i) {
+                fM.mapRect(&dst, fR);
+            }
+        }
+    }
+};
+DEF_BENCH( return new MapRectMatrixBench("maprect", false); )
+DEF_BENCH( return new MapRectMatrixBench("maprectscaletrans", true); )