Make nesting/running states a RunLoop rather than a MessageLoop concept.

components/omnibox/browser/autocomplete_provider_unittest.cc

 // Copyright (c) 2012 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 "components/omnibox/browser/autocomplete_provider.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 56 matching lines @@
  public:
   AutocompleteProviderClientWithClosure() {}
 
   void set_closure(const base::Closure& closure) { closure_ = closure; }
 
  private:
   void OnAutocompleteControllerResultReady(
       AutocompleteController* controller) override {
     if (!closure_.is_null())
       closure_.Run();
-    if (base::MessageLoop::current()->is_running())
+    if (base::RunLoop::IsRunningOnCurrentThread())
       base::MessageLoop::current()->QuitWhenIdle();
   }
 
   base::Closure closure_;
 
   DISALLOW_COPY_AND_ASSIGN(AutocompleteProviderClientWithClosure);
 };
 
 }  // namespace
 
@@ skipping 676 matching lines @@
   EXPECT_FALSE(search_provider_field_trial_triggered_in_session());
   url = GetDestinationURL(match, base::TimeDelta::FromMilliseconds(2456));
   EXPECT_EQ("//aqs=chrome.0.69i57j69i58j5l2j0l3j69i59.2456j0j4&", url.path());
 
   // Test page classification and field trial triggered set.
   set_search_provider_field_trial_triggered_in_session(true);
   EXPECT_TRUE(search_provider_field_trial_triggered_in_session());
   url = GetDestinationURL(match, base::TimeDelta::FromMilliseconds(2456));
   EXPECT_EQ("//aqs=chrome.0.69i57j69i58j5l2j0l3j69i59.2456j1j4&", url.path());
 }