QUIC - Added histograms to track the failure reasons to read or parse or

QUIC - Added histograms to track the failure reasons to read or parse or
write from or to disk cache.

Histograms added:
  + Net.QuicDiskCache.APICall - number of times read or parse or
    write API calls are called.
  + Net.QuicDiskCache.FailureReason - failure reason to read or parse or
    write from or to disk cache.

Deleted or obsoleted Net.QuicDiskCache.EntryState.

Will delete these histograms after we get some data on Android regarding
why we are having low 0RTT (or no quic server config).

R=asvitkine@chromium.org, rch@chromium.org,jar@chromium.org

Review URL: https://codereview.chromium.org/691263002

Cr-Commit-Position: refs/heads/master@{#302290}