cc: Remove FakeThread, use SingleThreadTaskRunner in scheduling classes.

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 65821bec5f52c8b32547884a931fa24fbb22ca69..ad37ab731dcc338e369d05b877ff5bdc40886302 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -14,6 +14,7 @@
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/animation/timing_function.h"
 #include "cc/base/math_util.h"
+#include "cc/base/thread.h"
 #include "cc/base/util.h"
 #include "cc/debug/debug_rect_history.h"
 #include "cc/debug/frame_rate_counter.h"
@@ -775,7 +776,7 @@ void LayerTreeHostImpl::UpdateBackgroundAnimateTicking(
     time_source_client_adapter_ = LayerTreeHostImplTimeSourceAdapter::Create(
         this,
         DelayBasedTimeSource::Create(LowFrequencyAnimationInterval(),
-                                     proxy_->CurrentThread()));
+                                     proxy_->CurrentThread()->TaskRunner()));
   }
 
   time_source_client_adapter_->SetActive(enabled);