Make sure we get at least one progress callback

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 f45e4fd08d3b295532d1cef07f1bb7fe4b1dc505..fed8e2dccadfc9c75e866859cf9f5a0b7442017b 100644
--- a/media/blink/multibuffer_data_source.h
+++ b/media/blink/multibuffer_data_source.h
@@ -162,12 +162,14 @@ class MEDIA_BLINK_EXPORT MultibufferDataSource : public DataSource {
   // MultiBufferReader progress callback.
   void ProgressCallback(int64_t begin, int64_t end);
 
+  // Update progress based on current reader state.
+  void UpdateProgress();
+
   // call downloading_cb_ if needed.
   // If |force_loading| is true, we call downloading_cb_ and tell it that
   // 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();