Sync from upstream.
Descriptions:
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Add result grouping to the ResultSpecProto to allow callers to limit the number of results returned per group of namespace.
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Implement PersistToDisk(LITE) to expose a LITE option for PersistToDisk that only persists the ground truth.
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Add per-namespace storage info.
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Add score to SearchResult.
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Migrate IndexProcessorTest, DocHitInfoIteratorFilterTest, DocHitInfoIteratorSectionRestrictTest to use SchemaBuilder
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Migrate ScorerTest and ScoringProcessorTest to use SchemaBuilder
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Add licensing header for storage.proto.
Change-Id: I5cbdd8045036dc38cf00191a2eac56cc6f2d3443
30 files changed