Implement caching in the tessellating path renderer, including strokes.

tests/TessellatingPathRendererTests.cpp

Index: tests/TessellatingPathRendererTests.cpp
diff --git a/tests/TessellatingPathRendererTests.cpp b/tests/TessellatingPathRendererTests.cpp
index dbfd8250383fc92f3804d6dc34184fa97b21e629..fb901c6824925f279188d86686e5e2d5176c0882 100644
--- a/tests/TessellatingPathRendererTests.cpp
+++ b/tests/TessellatingPathRendererTests.cpp
@@ -247,6 +247,8 @@ static void test_path(GrDrawTarget* dt, GrRenderTarget* rt, GrResourceProvider*
     args.fPath = &path;
     args.fStroke = &stroke;
     args.fAntiAlias = false;
+    args.fOrigSrcPath = nullptr;
+    args.fOrigStrokeInfo = nullptr;
     tess.drawPath(args);
 }