This is adds metrics to the generic ingestion module. It captures metrics about all stages of the ingestion process and allows to distinct between results being ingested by the polling process and event driven results.
This is adds metrics to the generic ingestion module. It captures metrics about all stages of the ingestion process and allows to distinct between results being ingested by the polling process and event driven results.

Events will be implemented soon and we will use that distinction to track throughput when we operate in an event driven mode.

BUG=skia:

Review URL: https://codereview.chromium.org/1468053002

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot