SetNeedsRedraw directly when updating a visible tile.

cc/test/fake_picture_pile_impl.h

Index: cc/test/fake_picture_pile_impl.h
diff --git a/cc/test/fake_picture_pile_impl.h b/cc/test/fake_picture_pile_impl.h
index f1a9d31ad3da684c651b42ed7484c39dae8ef2a8..99b2130914f36f2d0a9b7a2b139fd56966aa8abb 100644
--- a/cc/test/fake_picture_pile_impl.h
+++ b/cc/test/fake_picture_pile_impl.h
@@ -10,6 +10,7 @@
 #include "cc/test/fake_content_layer_client.h"
 
 namespace cc {
+class ThreadBlocker;
 
 class FakePicturePileImpl : public PicturePileImpl {
  public:
@@ -23,6 +24,14 @@ class FakePicturePileImpl : public PicturePileImpl {
       CreateEmptyPileThatThinksItHasRecordings(const gfx::Size& tile_size,
                                                const gfx::Size& layer_bounds);
   static scoped_refptr<FakePicturePileImpl> CreateInfiniteFilledPile();
+  static scoped_refptr<FakePicturePileImpl> CreateFromPile(
+      const PicturePile* other,
+      ThreadBlocker* blocker);
+
+  // Hi-jack the PlaybackToCanvas method to delay its completion.
+  void PlaybackToCanvas(SkCanvas* canvas,
+                        const gfx::Rect& canvas_rect,
+                        float contents_scale) const override;
 
   TilingData& tiling() { return tiling_; }
 
@@ -84,11 +93,12 @@ class FakePicturePileImpl : public PicturePileImpl {
 
  protected:
   FakePicturePileImpl();
-  explicit FakePicturePileImpl(const PicturePile* other);
+  FakePicturePileImpl(const PicturePile* other, ThreadBlocker* blocker);
   ~FakePicturePileImpl() override;
 
   FakeContentLayerClient client_;
   SkPaint default_paint_;
+  ThreadBlocker* raster_thread_blocker_;
   SkTileGridFactory::TileGridInfo tile_grid_info_;
 };