try to speed-up maprect + round2i + contains

include/core/SkRect.h

Index: include/core/SkRect.h
diff --git a/include/core/SkRect.h b/include/core/SkRect.h
index 39cbb330f82b207cd6a508570fe41f1372353590..c71d71259b6fbdda35d5ef6bc2d2cb0a854be44b 100644
--- a/include/core/SkRect.h
+++ b/include/core/SkRect.h
@@ -10,6 +10,7 @@
 
 #include "SkPoint.h"
 #include "SkSize.h"
+#include "../private/SkNx.h"
 
 struct SkRect;
 
@@ -869,7 +870,28 @@ public:
         this->roundOut(&ir);
         return ir;
     }
-    
+
+    /**
+     *  Round the rect's values and return the result as a new SkIRect.
+     *  This follows the same semantics as SkScalarRoundToInt().
+     */
+    SkIRect round2i() const {
+        SkIRect dst;
+        Sk4s rd = (Sk4s::Load(&fLeft) + Sk4s(0.5)).floor();
+        SkNx_cast<int32_t>(rd).store(&dst.fLeft);
+        return dst;
+    }
+
+    /**
+     *  Round the rect's values and return the result as a new SkRect.
+     *  This follows the same semantics as SkScalarRoundToScalar().
+     */
+    SkRect round2s() const {
+        SkRect dst;
+        (Sk4s::Load(&fLeft) + Sk4s(0.5)).floor().store(&dst.fLeft);
+        return dst;
+    }
+
     /**
      *  Swap top/bottom or left/right if there are flipped (i.e. if width()
      *  or height() would have returned a negative value.) This should be called