Revert of cc: Cleanup tile manager a bit.

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 707e5183e3022bd21d637a311a329f715f6b8cbb..91ae9ab9340c01911f0369b3ff9072dc65694e82 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -215,15 +215,13 @@
                                       !settings.single_thread_proxy_scheduler),
       // Must be initialized after is_synchronous_single_threaded_ and
       // task_runner_provider_.
-      // TODO(vmpstr): TileManager takes a scoped reftr for the task runner,
-      // figure out if it actually needs a ref or whether it can use a raw
-      // pointer.
-      tile_manager_(new TileManager(this,
-                                    GetTaskRunner(),
-                                    is_synchronous_single_threaded_
-                                        ? std::numeric_limits<size_t>::max()
-                                        : settings.scheduled_raster_task_limit,
-                                    settings.use_partial_raster)),
+      tile_manager_(
+          TileManager::Create(this,
+                              GetTaskRunner(),
+                              is_synchronous_single_threaded_
+                                  ? std::numeric_limits<size_t>::max()
+                                  : settings.scheduled_raster_task_limit,
+                              settings.use_partial_raster)),
       pinch_gesture_active_(false),
       pinch_gesture_end_should_clear_scrolling_layer_(false),
       fps_counter_(