Remove calls to deprecated MessageLoop methods in mojo.

mojo/public/cpp/bindings/tests/router_unittest.cc

 // Copyright 2014 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 "mojo/public/cpp/bindings/lib/router.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 10 matching lines @@
 class RouterTest : public testing::Test {
  public:
   RouterTest() {}
 
   void SetUp() override {
     CreateMessagePipe(nullptr, &handle0_, &handle1_);
   }
 
   void TearDown() override {}
 
-  void PumpMessages() { loop_.RunUntilIdle(); }
+  void PumpMessages() { base::RunLoop().RunUntilIdle(); }
 
  protected:
   ScopedMessagePipeHandle handle0_;
   ScopedMessagePipeHandle handle1_;
 
  private:
   base::MessageLoop loop_;
 };
 
 TEST_F(RouterTest, BasicRequestResponse) {
@@ skipping 265 matching lines @@
     EXPECT_TRUE(generator.has_responder());
   }
 
   EXPECT_FALSE(generator.responder_is_valid());
   generator.CompleteWithResponse();  // This should end up doing nothing.
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo