Make SkPath fFirstDirection atomic to fix tsan.

include/core/SkPath.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPath_DEFINED
 #define SkPath_DEFINED
 
@@ skipping 920 matching lines @@
         kFillType_SerializationShift = 8,   // requires 8 bits
         // low-8-bits are version
     };
 
     enum SerializationVersions {
         kPathPrivFirstDirection_Version = 1,
 
         kCurrent_Version = 1
     };
 
-    SkAutoTUnref<SkPathRef> fPathRef;
+    SkAutoTUnref<SkPathRef>   fPathRef;
 
-    int                 fLastMoveToIndex;
-    uint8_t             fFillType;
-    mutable uint8_t     fConvexity;
-    mutable uint8_t     fFirstDirection;    // SkPathPriv::FirstDirection
-    mutable SkBool8     fIsVolatile;
+    int                       fLastMoveToIndex;
+    uint8_t                   fFillType;
+    mutable uint8_t           fConvexity;
+    mutable SkAtomic<uint8_t> fFirstDirection;    // SkPathPriv::FirstDirection
+    mutable SkBool8           fIsVolatile;
 
     /** Resets all fields other than fPathRef to their initial 'empty' values.
      *  Assumes the caller has already emptied fPathRef.
      *  On Android increments fGenerationID without reseting it.
      */
     void resetFields();
 
     /** Sets all fields other than fPathRef to the values in 'that'.
      *  Assumes the caller has already set fPathRef.
      *  Doesn't change fGenerationID or fSourcePath on Android.
@@ skipping 44 matching lines @@
     void setPt(int index, SkScalar x, SkScalar y);
 
     friend class SkAutoPathBoundsUpdate;
     friend class SkAutoDisableOvalCheck;
     friend class SkAutoDisableDirectionCheck;
     friend class SkBench_AddPathTest; // perf test reversePathTo
     friend class PathTest_Private; // unit test reversePathTo
 };
 
 #endif