Remove remaining calls to deprecated MessageLoop methods.

services/shell/tests/shell/shell_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <utility>
 
@@ skipping 165 matching lines @@
 
   // 1. Launch a process. (Actually, have the runner launch a process that
   //    launches a process.)
   test::mojom::DriverPtr driver;
   std::unique_ptr<Connection> connection =
       connector()->Connect("exe:shell_unittest_driver");
   connection->GetInterface(&driver);
 
   // 2. Wait for the target to connect to us. (via
   //    mojo:shell_unittest)
-  base::MessageLoop::current()->Run();
+  base::RunLoop().Run();
 
   EXPECT_FALSE(connection->IsPending());
   uint32_t remote_id = connection->GetRemoteInstanceID();
   EXPECT_NE(mojom::kInvalidInstanceID, remote_id);
 
   // 3. Validate that this test suite's name was received from the application
   //    manager.
   EXPECT_TRUE(ContainsInstanceWithName("mojo:shell_unittest"));
 
   // 4. Validate that the right applications/processes were created.
@@ skipping 11 matching lines @@
     // We learn about the target process id via a ping from it.
     EXPECT_EQ(target_id(), instance.id);
     EXPECT_EQ("exe:shell_unittest_target", instance.name);
     EXPECT_NE(base::kNullProcessId, instance.pid);
   }
 
   driver.set_connection_error_handler(
       base::Bind(&ShellTest::OnDriverQuit,
                  base::Unretained(this)));
   driver->QuitDriver();
-  base::MessageLoop::current()->Run();
+  base::RunLoop().Run();
 }
 
 }  // namespace shell