Implement caching in the tessellating path renderer, including strokes.

src/gpu/GrPathRenderer.h

Index: src/gpu/GrPathRenderer.h
diff --git a/src/gpu/GrPathRenderer.h b/src/gpu/GrPathRenderer.h
index e353d6876fc1669129a646864fea4adcfeef8f95..fb76dedff42b1727089b0508abe31f0655962351 100644
--- a/src/gpu/GrPathRenderer.h
+++ b/src/gpu/GrPathRenderer.h
@@ -144,6 +144,8 @@ public:
         const SkPath*               fPath;
         const GrStrokeInfo*         fStroke;
         bool                        fAntiAlias;
+        const SkPath*               fOrigSrcPath;
+        const GrStrokeInfo*         fOrigStrokeInfo;
     };
 
     /**
@@ -290,6 +292,8 @@ private:
         drawArgs.fPath = args.fPath;
         drawArgs.fStroke = args.fStroke;
         drawArgs.fAntiAlias = false;
+        drawArgs.fOrigSrcPath = nullptr;
+        drawArgs.fOrigStrokeInfo = nullptr;
         this->drawPath(drawArgs);
     }