fix multibuffer "is loading"

media/blink/multibuffer_data_source.h

Index: media/blink/multibuffer_data_source.h
diff --git a/media/blink/multibuffer_data_source.h b/media/blink/multibuffer_data_source.h
index fe89ca8e5b53068f4195c8fe4f3fc6937724e108..f45e4fd08d3b295532d1cef07f1bb7fe4b1dc505 100644
--- a/media/blink/multibuffer_data_source.h
+++ b/media/blink/multibuffer_data_source.h
@@ -167,6 +167,7 @@ class MEDIA_BLINK_EXPORT MultibufferDataSource : public DataSource {
   // we are currently loading, regardless of what reader_->IsLoading() says.
   // Caller must hold |lock_|.
   void UpdateLoadingState_Locked(bool force_loading);
+  void UpdateLoadingState();
 
   // Update |reader_|'s preload and buffer settings.
   void UpdateBufferSizes();