Determine test coverage for this case.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index dcb23093a4b720e443b77740cba1a282dffdc05d..2c8118083c66ed27b3a09d001f1a94c1199ce8d7 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -1047,8 +1047,10 @@ void RenderViewHostImpl::OnStartDragging(
   for (size_t i = 0; i < drop_data.file_system_files.size(); ++i) {
     storage::FileSystemURL file_system_url =
         file_system_context->CrackURL(drop_data.file_system_files[i].url);
-    if (policy->CanReadFileSystemFile(GetProcess()->GetID(), file_system_url))
+    if (policy->CanReadFileSystemFile(GetProcess()->GetID(), file_system_url)) {
+      CHECK(false);
       filtered_data.file_system_files.push_back(drop_data.file_system_files[i]);
+    }
   }
 
   float scale = GetScaleFactorForView(GetWidget()->GetView());