Move MessageLoop to base namespace.

chrome/browser/chromeos/login/user_image_loader.h

Index: chrome/browser/chromeos/login/user_image_loader.h
diff --git a/chrome/browser/chromeos/login/user_image_loader.h b/chrome/browser/chromeos/login/user_image_loader.h
index a3b7384ce602f1d386789b85d43f055511efd585..bc069cedd833999b53a7ba107ddd0f9d8a088c67 100644
--- a/chrome/browser/chromeos/login/user_image_loader.h
+++ b/chrome/browser/chromeos/login/user_image_loader.h
@@ -15,9 +15,12 @@
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/image_decoder.h"
 
-class MessageLoop;
 class SkBitmap;
 
+namespace base {
+class MessageLoop;
+}
+
 namespace chromeos {
 
 typedef base::SequencedWorkerPool::SequenceToken SequenceToken;
@@ -77,7 +80,7 @@ class UserImageLoader : public base::RefCountedThreadSafe<UserImageLoader>,
   virtual void OnDecodeImageFailed(const ImageDecoder* decoder) OVERRIDE;
 
   // The message loop object of the thread in which we notify the delegate.
-  MessageLoop* target_message_loop_;
+  base::MessageLoop* target_message_loop_;
 
   // Specify how the file should be decoded in the utility process.
   const ImageDecoder::ImageCodec image_codec_;