SetNeedsRedraw directly when updating a visible tile.

cc/test/fake_picture_pile.cc

Index: cc/test/fake_picture_pile.cc
diff --git a/cc/test/fake_picture_pile.cc b/cc/test/fake_picture_pile.cc
new file mode 100644
index 0000000000000000000000000000000000000000..12f7acac40bd5e0f3c80283e10bd01c0f782ccf1
--- /dev/null
+++ b/cc/test/fake_picture_pile.cc
@@ -0,0 +1,15 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cc/test/fake_picture_pile.h"
+
+#include "cc/test/fake_picture_pile_impl.h"
+
+namespace cc {
+
+scoped_refptr<RasterSource> FakePicturePile::CreateRasterSource() const {
+  return FakePicturePileImpl::CreateFromPile(this, raster_thread_blocker_);
+}
+
+}  // namespace cc