Convert drawPaint to drawRRect in simple cases

src/gpu/GrClipStackClip.cpp

Index: src/gpu/GrClipStackClip.cpp
diff --git a/src/gpu/GrClipStackClip.cpp b/src/gpu/GrClipStackClip.cpp
index 7138f4b68a1d42bf6211b2a9f1dd36adf556a494..d0a9d66c22b97a3b73a47e04b2363dc3950e978e 100644
--- a/src/gpu/GrClipStackClip.cpp
+++ b/src/gpu/GrClipStackClip.cpp
@@ -41,6 +41,27 @@ bool GrClipStackClip::quickContains(const SkRRect& rrect) const {
                                                   SkIntToScalar(fOrigin.fY)));
 }
 
+bool GrClipStackClip::isRRect(const SkRect& origRTBounds, SkRRect* rr, bool* aa) const {
+    if (!fStack) {
+        return false;
+    }
+    const SkRect* rtBounds = &origRTBounds;
+    SkRect tempRTBounds;
+    bool origin = fOrigin.fX || fOrigin.fY;
+    if (origin) {
+        tempRTBounds = origRTBounds;
+        tempRTBounds.offset(fOrigin.fX, fOrigin.fY);
+        rtBounds = &tempRTBounds;
+    }
+    if (fStack->isRRect(*rtBounds, rr, aa)) {
+        if (origin) {
+            rr->offset(-fOrigin.fX, -fOrigin.fY);
+        }
+        return true;
+    }
+    return false;
+}
+
 void GrClipStackClip::getConservativeBounds(int width, int height, SkIRect* devResult,
                                             bool* isIntersectionOfRects) const {
     if (!fStack) {