media: Make sure we transition back to a non-loading state

media/blink/multibuffer_data_source.cc

Index: media/blink/multibuffer_data_source.cc
diff --git a/media/blink/multibuffer_data_source.cc b/media/blink/multibuffer_data_source.cc
index a0e16e6138528bb2531889f20ebe92b077fea7af..249e4b1d7d8ad5cd3b281cfcdfcb1202446f72fc 100644
--- a/media/blink/multibuffer_data_source.cc
+++ b/media/blink/multibuffer_data_source.cc
@@ -424,8 +424,8 @@ void MultibufferDataSource::ReadTask() {
   } else {
     reader_->Wait(1, base::Bind(&MultibufferDataSource::ReadTask,
                                 weak_factory_.GetWeakPtr()));
-    UpdateLoadingState_Locked(false);
   }
+  UpdateLoadingState_Locked(false);
 }
 
 void MultibufferDataSource::StopInternal_Locked() {
@@ -546,15 +546,21 @@ void MultibufferDataSource::UpdateLoadingState_Locked(bool force_loading) {
     return;
   // Update loading state.
   bool is_loading = !!reader_ && reader_->IsLoading();
-  if (read_op_)
-    is_loading = true;
   if (force_loading || is_loading != loading_) {
-    loading_ = is_loading || force_loading;
-
-    if (!loading_ && cancel_on_defer_) {
+    bool loading = is_loading || force_loading;
+
+    if (!loading && cancel_on_defer_) {
+      if (read_op_) {
+        // We can't destroy the reader if a read operation is pending.
+        // UpdateLoadingState_Locked will be called again when the read
+        // operation is done.
+        return;
+      }
       reader_.reset(nullptr);
     }
 
+    loading_ = loading;
+
     // Callback could kill us, be sure to call it last.
     downloading_cb_.Run(loading_);
   }