Fast path for blurred round rects -- blur a small 9patch rect on the CPU

src/effects/SkBlurMask.cpp

Index: src/effects/SkBlurMask.cpp
diff --git a/src/effects/SkBlurMask.cpp b/src/effects/SkBlurMask.cpp
index 9b05e2f330323132f3360c33200b7a9fd66e20d5..c04a6f89f8d46783f2f232ec58c94977552edc24 100644
--- a/src/effects/SkBlurMask.cpp
+++ b/src/effects/SkBlurMask.cpp
@@ -475,14 +475,16 @@ void SkMask_FreeImage(uint8_t* image) {
     SkMask::FreeImage(image);
 }
 
-bool SkBlurMask::BoxBlur(SkMask* dst, const SkMask& src, SkScalar sigma, SkBlurStyle style,
-                         SkBlurQuality quality, SkIPoint* margin) {
+bool SkBlurMask::BoxBlur(SkMask* dst, const SkMask& src,
+                         SkScalar sigma, SkBlurStyle style, SkBlurQuality quality,
+                         SkIPoint* margin, bool force_quality) {
+
     if (src.fFormat != SkMask::kA8_Format) {
         return false;
     }
 
     // Force high quality off for small radii (performance)
-    if (sigma <= SkIntToScalar(2)) {
+    if (!force_quality && sigma <= SkIntToScalar(2)) {
         quality = kLow_SkBlurQuality;
     }