Remove use of deprecated MessageLoop methods in components.

components/precache/content/precache_manager_unittest.cc

Index: components/precache/content/precache_manager_unittest.cc
diff --git a/components/precache/content/precache_manager_unittest.cc b/components/precache/content/precache_manager_unittest.cc
index 151360ad0abb059b5967ccdda42fef2bc78117ba..27b167f31548ca8d25aba396be7d9e3e356e1944 100644
--- a/components/precache/content/precache_manager_unittest.cc
+++ b/components/precache/content/precache_manager_unittest.cc
@@ -325,7 +325,8 @@ TEST_F(PrecacheManagerTest, StartAndCancelPrecachingAfterURLsReceived) {
   // Run a task to get unfinished work, and to get hosts.
   for (int i = 0; i < 2; ++i) {
     base::RunLoop run_loop;
-    base::MessageLoop::current()->PostTask(FROM_HERE, run_loop.QuitClosure());
+    base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
+                                                  run_loop.QuitClosure());
     run_loop.Run();
   }
   // base::RunLoop().RunUntilIdle();