Implement vertex buffer caching in the tessellated path renderer.

src/gpu/GrTessellatingPathRenderer.h

Index: src/gpu/GrTessellatingPathRenderer.h
diff --git a/src/gpu/GrTessellatingPathRenderer.h b/src/gpu/GrTessellatingPathRenderer.h
index 79cafc99f520fe1a229bf52108528eda6657fd2f..4f0b638dd95bd8ff39b1eb87417afd81fc8dc1ed 100644
--- a/src/gpu/GrTessellatingPathRenderer.h
+++ b/src/gpu/GrTessellatingPathRenderer.h
@@ -16,7 +16,7 @@
  */
 class SK_API GrTessellatingPathRenderer : public GrPathRenderer {
 public:
-    GrTessellatingPathRenderer();
+    explicit GrTessellatingPathRenderer(GrContext*);
 
     bool canDrawPath(const GrDrawTarget*,
                      const GrPipelineBuilder*,
@@ -40,6 +40,8 @@ protected:
                     bool antiAlias) override;
 
     typedef GrPathRenderer INHERITED;
+private:
+    GrContext* fContext;
 };
 
 #endif