Add convenience overload of SkPointPriv::SetRectTriStrip that takes SkRect

Change-Id: Idf5bfafaf19c20f074f12d706b8b8984c5935e6d
Reviewed-on: https://skia-review.googlesource.com/129185
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/gm/convexpolyeffect.cpp b/gm/convexpolyeffect.cpp
index ca27e28..8942602 100644
--- a/gm/convexpolyeffect.cpp
+++ b/gm/convexpolyeffect.cpp
@@ -86,8 +86,7 @@
             return;
         }
 
-        SkPointPriv::SetRectTriStrip(verts, fRect.fLeft, fRect.fTop, fRect.fRight, fRect.fBottom,
-                               sizeof(SkPoint));
+        SkPointPriv::SetRectTriStrip(verts, fRect, sizeof(SkPoint));
 
         helper.recordDraw(
                 target, gp.get(),