allow one zero length dash

src/utils/SkDashPathPriv.h

Index: src/utils/SkDashPathPriv.h
diff --git a/src/utils/SkDashPathPriv.h b/src/utils/SkDashPathPriv.h
index 7453dcec82e35829b80db097d005746d0996782b..c67c7633337be53d4b88cbbd03de9eae6d46163b 100644
--- a/src/utils/SkDashPathPriv.h
+++ b/src/utils/SkDashPathPriv.h
@@ -17,7 +17,7 @@ namespace SkDashPath {
      * adjusted to be between 0 and intervalLength. The result will be stored in adjustedPhase.
      * If adjustedPhase is nullptr then it is assumed phase is already between 0 and intervalLength
      */
-    void CalcDashParameters(SkScalar phase, const SkScalar intervals[], int32_t count,
+    bool CalcDashParameters(SkScalar phase, const SkScalar intervals[], int32_t count,
                             SkScalar* initialDashLength, int32_t* initialDashIndex,
                             SkScalar* intervalLength, SkScalar* adjustedPhase = nullptr);