Remove calls to deprecated MessageLoop methods in cc.

cc/test/layer_tree_test.cc

Index: cc/test/layer_tree_test.cc
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index a08978e39497497c049aaae9bdd28b9803f79fd8..81d153814efbef8479813b555965ec14ba87a0c5 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -7,6 +7,7 @@
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
+#include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/animation/animation.h"
@@ -888,7 +889,7 @@ void LayerTreeTest::RunTest(CompositorMode mode, bool delegating_renderer) {
         base::TimeDelta::FromSeconds(timeout_seconds_));
   }
 
-  base::MessageLoop::current()->Run();
+  base::RunLoop().Run();
   DestroyLayerTreeHost();
 
   timeout_.Cancel();