update sampleapp for stroking experiment

gm/pathfill.cpp

Index: gm/pathfill.cpp
diff --git a/gm/pathfill.cpp b/gm/pathfill.cpp
index 6b37c6693a94032992c48b6aad7667d9f29ff8e0..461a4f5fc82d69652cf2f2488e736bd925160762 100644
--- a/gm/pathfill.cpp
+++ b/gm/pathfill.cpp
@@ -117,14 +117,13 @@ static const MakePathProc gProcs[] = {
 class PathFillGM : public skiagm::GM {
     SkPath  fPath[N];
     SkScalar fDY[N];
-public:
-    PathFillGM() {
+protected:
+    void onOnceBeforeDraw() SK_OVERRIDE {
         for (size_t i = 0; i < N; i++) {
             fDY[i] = gProcs[i](&fPath[i]);
         }
     }
 
-protected:
 
     SkString onShortName() SK_OVERRIDE {
         return SkString("pathfill");
@@ -152,15 +151,13 @@ private:
 class PathInverseFillGM : public skiagm::GM {
     SkPath  fPath[N];
     SkScalar fDY[N];
-public:
-    PathInverseFillGM() {
+protected:
+    void onOnceBeforeDraw() SK_OVERRIDE {
         for (size_t i = 0; i < N; i++) {
             fDY[i] = gProcs[i](&fPath[i]);
         }
     }
 
-protected:
-
     SkString onShortName() SK_OVERRIDE {
         return SkString("pathinvfill");
     }