path_stroke_with_zero_length: turn off drawFat() by default.

gm/path_stroke_with_zero_length.cpp

Index: gm/path_stroke_with_zero_length.cpp
diff --git a/gm/path_stroke_with_zero_length.cpp b/gm/path_stroke_with_zero_length.cpp
index ab9273626c352580b07c131135fc02ad13393683..c69fe5c0c78d423ee0d6b11ac458834c701abd65 100644
--- a/gm/path_stroke_with_zero_length.cpp
+++ b/gm/path_stroke_with_zero_length.cpp
@@ -91,7 +91,7 @@ protected:
                 if (indexMask & (1 << index)) {
                     canvas->drawPath(path, paint);
                 }
-                if (paint.getStrokeWidth() < 2) {
+                if (this->getMode() == skiagm::GM::kSample_Mode && paint.getStrokeWidth() < 2) {
                     drawFat(canvas, path, paint, index);
                 }
                 ++index;