Currently, we autofile bugs for tests belong to au, bvt_*. paygen_*, and sanity suites. From my respective, the reasons we have so many autofiled bugs are either WontFix or duplicate are
1.  Most of them don't have owner or cc'd. The bugs are just filed and buried.
2. The Anchor used in the bug sometimes is so specific. E.g., include the payload version. 
https://bugs.chromium.org/p/chromium/issues/detail?id=592528
https://bugs.chromium.org/p/chromium/issues/detail?id=592527

In the short term, we can optimize the anchor to merge more duplicated issues. 

@Fang / Charlene - feel free to add more context!