Do circular clipping in normalized space

gm/circularclips.cpp

Index: gm/circularclips.cpp
diff --git a/gm/circularclips.cpp b/gm/circularclips.cpp
index 4a98de4efa7bba791bd6e4ab691ee5db25cdc4cc..15f583f67de2fc92e709828b96c80f10e42d6fab 100644
--- a/gm/circularclips.cpp
+++ b/gm/circularclips.cpp
@@ -49,6 +49,20 @@ protected:
 
         SkPaint fillPaint;
 
+        // Giant background circular clips (AA, non-inverted, replace/isect)
+        fillPaint.setColor(0x80808080);
+        canvas->save();
+        canvas->scale(10, 10);
+        canvas->translate(-((fX1 + fX2)/2 - fR), -(fY - 2*fR/3));
+        canvas->clipPath(fCircle1, SkRegion::kReplace_Op, true);
+        canvas->clipPath(fCircle2, SkRegion::kIntersect_Op, true);
+
+        canvas->drawRect(rect, fillPaint);
+
+        canvas->restore();
+      
+        fillPaint.setColor(0xFF000000);
+
         for (size_t i = 0; i < 4; i++) {
             fCircle1.toggleInverseFillType();
             if (i % 2 == 0) {