cc: Use multiple PrepareTiles approaches

cc/trees/layer_tree_host_unittest_animation.cc

Index: cc/trees/layer_tree_host_unittest_animation.cc
diff --git a/cc/trees/layer_tree_host_unittest_animation.cc b/cc/trees/layer_tree_host_unittest_animation.cc
index ed27a03a2f8b12bce15b9cc2814157729c267ce8..a0e73996977a5477c0bc7ac9c6519fcc4738ca4f 100644
--- a/cc/trees/layer_tree_host_unittest_animation.cc
+++ b/cc/trees/layer_tree_host_unittest_animation.cc
@@ -607,7 +607,8 @@ class LayerTreeHostAnimationTestCheckerboardDoesntStartAnimations
   void InitializeSettings(LayerTreeSettings* settings) override {
     // Make sure that drawing many times doesn't cause a checkerboarded
     // animation to start so we avoid flake in this test.
-    settings->timeout_and_draw_when_animation_checkerboards = false;
+    // TODO(brianderson): Figure out what to do to make this test not flaky.
+    // settings->timeout_and_draw_when_animation_checkerboards = false;
   }
 
   void BeginTest() override {