add roundOut that returns its result

src/core/SkBitmapDevice.cpp

Index: src/core/SkBitmapDevice.cpp
diff --git a/src/core/SkBitmapDevice.cpp b/src/core/SkBitmapDevice.cpp
index 5204fdb53e93476b00a56c295b09a451ac867dc0..9df7c9b65584ad3a56a3e077beb03f80451697e3 100644
--- a/src/core/SkBitmapDevice.cpp
+++ b/src/core/SkBitmapDevice.cpp
@@ -260,8 +260,7 @@ void SkBitmapDevice::drawBitmapRect(const SkDraw& draw, const SkBitmap& bitmap,
 
         // since we may need to clamp to the borders of the src rect within
         // the bitmap, we extract a subset.
-        SkIRect srcIR;
-        tmpSrc.roundOut(&srcIR);
+        const SkIRect srcIR = tmpSrc.roundOut();
         if(bitmap.pixelRef()->getTexture()) {
             // Accelerated source canvas, don't use extractSubset but readPixels to get the subset.
             // This way, the pixels are copied in CPU memory instead of GPU memory.