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 9712ecc4757162fd05a966c5dbf3bffd54e50fb1..f33817adee0830bf2fea88c82b681f9cb544b086 100644
--- a/src/effects/SkBlurMask.cpp
+++ b/src/effects/SkBlurMask.cpp
@@ -477,14 +477,14 @@ void SkMask_FreeImage(uint8_t* image) {
 
 bool SkBlurMask::BoxBlur(SkMask* dst, const SkMask& src,
                          SkScalar sigma, Style style, Quality quality,
-                         SkIPoint* margin) {
+                         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_Quality;
     }