SetNeedsRedraw directly when updating a visible tile.

cc/BUILD.gn

Index: cc/BUILD.gn
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 37e471d4fe08029a7e22cbe21bcb56de195abc0e..27edf88ddc6de83894436612ead94b1709dceb29 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -542,6 +542,7 @@ source_set("test_support") {
     "test/fake_picture_layer_impl.h",
     "test/fake_picture_layer_tiling_client.cc",
     "test/fake_picture_layer_tiling_client.h",
+    "test/fake_picture_pile.cc",
     "test/fake_picture_pile.h",
     "test/fake_picture_pile_impl.cc",
     "test/fake_picture_pile_impl.h",
@@ -627,6 +628,8 @@ source_set("test_support") {
     "test/test_tile_priorities.h",
     "test/test_web_graphics_context_3d.cc",
     "test/test_web_graphics_context_3d.h",
+    "test/thread_blocker.cc",
+    "test/thread_blocker.h",
     "test/tiled_layer_test_common.cc",
     "test/tiled_layer_test_common.h",
   ]