Remove IOThread::message_loop().

content/browser/browser_thread_impl.cc

Index: content/browser/browser_thread_impl.cc
diff --git a/content/browser/browser_thread_impl.cc b/content/browser/browser_thread_impl.cc
index 0025f77841e1dd57cc876c0d3bd2eda13a4ee443..9f8cc35a157f351321cf113f3df572a510161aab 100644
--- a/content/browser/browser_thread_impl.cc
+++ b/content/browser/browser_thread_impl.cc
@@ -401,6 +401,10 @@ base::Thread* BrowserThread::UnsafeGetBrowserThread(ID identifier) {
   return thread;
 }
 
+MessageLoop* BrowserThread::UnsafeGetMessageLoop(ID identifier) {
+  return UnsafeGetBrowserThread(identifier)->message_loop();
+}
+
 void BrowserThread::SetDelegate(ID identifier,
                                 BrowserThreadDelegate* delegate) {
   using base::subtle::AtomicWord;