Move MessageLoop to base namespace.

chrome/browser/sync/glue/sync_backend_registrar.h

Index: chrome/browser/sync/glue/sync_backend_registrar.h
diff --git a/chrome/browser/sync/glue/sync_backend_registrar.h b/chrome/browser/sync/glue/sync_backend_registrar.h
index a02c5d895ac3a47d15bd7377ce36f30c110865e2..f43e2791318838fe54e9e2db9269c73886c065ab 100644
--- a/chrome/browser/sync/glue/sync_backend_registrar.h
+++ b/chrome/browser/sync/glue/sync_backend_registrar.h
@@ -16,9 +16,12 @@
 #include "sync/internal_api/public/engine/model_safe_worker.h"
 #include "sync/internal_api/public/sync_manager.h"
 
-class MessageLoop;
 class Profile;
 
+namespace base {
+class MessageLoop;
+}
+
 namespace syncer {
 struct UserShare;
 }  // namespace syncer
@@ -37,7 +40,7 @@ class SyncBackendRegistrar : public syncer::SyncManager::ChangeDelegate {
   // |sync_loop|.  Must be created on the UI thread.
   SyncBackendRegistrar(const std::string& name,
                        Profile* profile,
-                       MessageLoop* sync_loop);
+                       base::MessageLoop* sync_loop);
 
   // Informs the SyncBackendRegistrar of the currently enabled set of types.
   // These types will be placed in the passive group.  This function should be
@@ -128,7 +131,7 @@ class SyncBackendRegistrar : public syncer::SyncManager::ChangeDelegate {
 
   Profile* const profile_;
 
-  MessageLoop* const sync_loop_;
+  base::MessageLoop* const sync_loop_;
 
   const scoped_refptr<UIModelWorker> ui_worker_;