SkPath -> PreCachedPath

SkPath is not threadsafe.  Gotta use PreCachedPath.

TSAN is showing a race in SkPathRef::genID() to write the fGenerationID.

Change-Id: I42d6ecadaa754a3c6796ca465981de430a0abb84
Reviewed-on: https://skia-review.googlesource.com/17279
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/src/core/SkRecords.h b/src/core/SkRecords.h
index a63ef1c..3897304 100644
--- a/src/core/SkRecords.h
+++ b/src/core/SkRecords.h
@@ -348,7 +348,7 @@
         sk_sp<SkVertices> vertices;
         SkBlendMode bmode);
 RECORD(DrawShadowRec, kDraw_Tag,
-       SkPath path;
+       PreCachedPath path;
        SkDrawShadowRec rec);
 RECORD(DrawAnnotation, 0,  // TODO: kDraw_Tag, skia:5548
        SkRect rect;