add default arg so android can bulid

Bug: skia:
Change-Id: I2bb10edba9a39f20691398a2a0a01b1da2709fcd
Reviewed-on: https://skia-review.googlesource.com/17761
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/src/utils/SkPatchUtils.h b/src/utils/SkPatchUtils.h
index 9627f74..75c10e8 100644
--- a/src/utils/SkPatchUtils.h
+++ b/src/utils/SkPatchUtils.h
@@ -49,7 +49,7 @@
 
     static sk_sp<SkVertices> MakeVertices(const SkPoint cubics[12], const SkColor colors[4],
                                           const SkPoint texCoords[4], int lodX, int lodY,
-                                          bool interpColorsLinearly);
+                                          bool interpColorsLinearly = false);
 };
 
 #endif