use inttoscalar to fix warning

gm/filterbitmap.cpp

Index: gm/filterbitmap.cpp
diff --git a/gm/filterbitmap.cpp b/gm/filterbitmap.cpp
index 371666dff545f7f12333789093900e1540603e3e..d7e2352fbca045a7b9ce7eb709e93a4f32016e33 100644
--- a/gm/filterbitmap.cpp
+++ b/gm/filterbitmap.cpp
@@ -34,10 +34,10 @@ static void load_bm(SkBitmap* bm) {
 }
 
 static SkSize computeSize(const SkBitmap& bm, const SkMatrix& mat) {
-    SkRect bounds = { 0, 0, bm.width(), bm.height() };
+    SkRect bounds = SkRect::MakeWH(SkIntToScalar(bm.width()),
+                                   SkIntToScalar(bm.height()));
     mat.mapRect(&bounds);
-    return SkSize::Make(SkIntToScalar(bounds.width()),
-                        SkIntToScalar(bounds.height()));
+    return SkSize::Make(bounds.width(), bounds.height());
 }
 
 static void draw_col(SkCanvas* canvas, const SkBitmap& bm, const SkMatrix& mat,