MSE - Fix crash caused by incorrect GC of GOP with next buffer position

media/filters/source_buffer_range.cc

Index: media/filters/source_buffer_range.cc
diff --git a/media/filters/source_buffer_range.cc b/media/filters/source_buffer_range.cc
index bd99bc01d3c395d099b061d94fda12607ba05818..58828688d5838dfeb3aa8cd7f8da9138b9a93bca 100644
--- a/media/filters/source_buffer_range.cc
+++ b/media/filters/source_buffer_range.cc
@@ -231,6 +231,7 @@ bool SourceBufferRange::TruncateAt(
 }
 
 size_t SourceBufferRange::DeleteGOPFromFront(BufferQueue* deleted_buffers) {
+  DCHECK(!buffers_.empty());
   DCHECK(!FirstGOPContainsNextBufferPosition());
   DCHECK(deleted_buffers);
 
@@ -279,6 +280,7 @@ size_t SourceBufferRange::DeleteGOPFromFront(BufferQueue* deleted_buffers) {
 }
 
 size_t SourceBufferRange::DeleteGOPFromBack(BufferQueue* deleted_buffers) {
+  DCHECK(!buffers_.empty());
   DCHECK(!LastGOPContainsNextBufferPosition());
   DCHECK(deleted_buffers);