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

content/browser/browser_main_runner.cc

Index: content/browser/browser_main_runner.cc
diff --git a/content/browser/browser_main_runner.cc b/content/browser/browser_main_runner.cc
index 0d986c057b7be1c05486d300d46e34d3cb6e8aef..2499e1b27261c4fd18de37e5ce0d42757eaf4838 100644
--- a/content/browser/browser_main_runner.cc
+++ b/content/browser/browser_main_runner.cc
@@ -14,6 +14,7 @@
 #include "base/metrics/statistics_recorder.h"
 #include "base/profiler/scoped_profile.h"
 #include "base/profiler/scoped_tracker.h"
+#include "base/run_loop.h"
 #include "base/time/time.h"
 #include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 #include "base/trace_event/trace_event.h"
@@ -207,7 +208,7 @@ class BrowserMainRunnerImpl : public BrowserMainRunner {
       // Forcefully terminates the RunLoop inside MessagePumpForUI, ensuring
       // proper shutdown for content_browsertests. Shutdown() is not used by
       // the actual browser.
-      if (base::MessageLoop::current()->is_running())
+      if (base::RunLoop::IsRunningOnCurrentThread())
         base::MessageLoop::current()->QuitNow();
   #endif
       main_loop_.reset(NULL);