diff --git a/ipc/chromium/src/base/message_loop.cc b/ipc/chromium/src/base/message_loop.cc
index b8e7138ce11f..27c1e3625a87 100644
--- a/ipc/chromium/src/base/message_loop.cc
+++ b/ipc/chromium/src/base/message_loop.cc
@@ -125,6 +125,9 @@ MessageLoop::MessageLoop(Type type)
     pump_ = new mozilla::ipc::MessagePumpForNonMainUIThreads();
     return;
 #endif
+  default:
+    // Create one of Chromium's standard MessageLoop types below.
+    break;
   }
 
 #if defined(OS_WIN)