Attempt to throw away rrect clips of rrects.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2241273003

Review-Url: https://codereview.chromium.org/2241273003
diff --git a/src/gpu/GrClipStackClip.cpp b/src/gpu/GrClipStackClip.cpp
index 6cb216e..a3a0de5 100644
--- a/src/gpu/GrClipStackClip.cpp
+++ b/src/gpu/GrClipStackClip.cpp
@@ -30,6 +30,14 @@
                                                  SkIntToScalar(fOrigin.y())));
 }
 
+bool GrClipStackClip::quickContains(const SkRRect& rrect) const {
+    if (!fStack) {
+        return true;
+    }
+    return fStack->quickContains(rrect.makeOffset(SkIntToScalar(fOrigin.fX),
+                                                  SkIntToScalar(fOrigin.fY)));
+}
+
 void GrClipStackClip::getConservativeBounds(int width, int height, SkIRect* devResult,
                                             bool* isIntersectionOfRects) const {
     if (!fStack) {