Add control over whether lines are special cased in SkDashPath. Disable when called from GrShape.

src/utils/SkDashPathPriv.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDashPathPriv_DEFINED
 #define SkDashPathPriv_DEFINED
 
 #include "SkPathEffect.h"
 
 namespace SkDashPath {
-    /*
+    /**
      * Calculates the initialDashLength, initialDashIndex, and intervalLength based on the
      * inputed phase and intervals. If adjustedPhase is passed in, then the phase will be
      * 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
      *
      * Caller should have already used ValidDashPath to exclude invalid data.
      */
     void CalcDashParameters(SkScalar phase, const SkScalar intervals[], int32_t count,
                             SkScalar* initialDashLength, int32_t* initialDashIndex,
                             SkScalar* intervalLength, SkScalar* adjustedPhase = nullptr);
 
     bool FilterDashPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect*,
                         const SkPathEffect::DashInfo& info);
 
-    /*
-     * Caller should have already used ValidDashPath to exclude invalid data.
+    /** See comments for InternalFilter */
+    enum class StrokeRecApplication {
+        kDisallow,
+        kAllow,
+    };
+
+    /**
+     * Caller should have already used ValidDashPath to exclude invalid data. Typically, this leaves
+     * the strokeRec unmodified. However, for some simple shapes (e.g. a line) it may directly
+     * evaluate the dash and stroke to produce a stroked output path with a fill strokeRec. Passing
+     * true for disallowStrokeRecApplication turns this behavior off.
      */
     bool InternalFilter(SkPath* dst, const SkPath& src, SkStrokeRec* rec,
                         const SkRect* cullRect, const SkScalar aIntervals[],
                         int32_t count, SkScalar initialDashLength, int32_t initialDashIndex,
-                        SkScalar intervalLength);
+                        SkScalar intervalLength,
+                        StrokeRecApplication = StrokeRecApplication::kAllow);
 
     bool ValidDashPath(SkScalar phase, const SkScalar intervals[], int32_t count);
 }
 
 #endif