am 15b8a778: Merge branch \'rewrite-metrics\' into merge-metrics

* commit '15b8a778': (200 commits)
  metrics: Import protobufs from Chromium.
  metrics: replace "Logging.*" with "Platform.*"
  platform2: Fix issues with new version of libchrome
  init: fix typo and prevent startup error
  metrics: Add a check for abnormally small messages to prevent crashes
  libchromeos: Switch http Response to use streams
  Revert "metrics: Fix the import path of protobufs."
  metrics: Fix the import path of protobufs.
  platform2: Switch over to libchrome r323904
  metrics: add TPM.EarlyResetDuringCommand CrOS event.
  delete __STDC_{FORMAT,LIMIT}_MACROS
  metrics: make metrics library also use /var/lib/metrics/uma-events
  metrics: tell what file we can't open on error
  metrics: move sample file from /var/run to /var/lib
  metrics: don't upload metrics when metrics are disabled
  metrics: Disable uploader on non-official build.
  platform2: Switch over to using base64 functions from libchromeos
  metrics: fix -Winconsistent-missing-override warning
  metrics: Fix upload_service to work with base::MessageLoop
  metrics: generate app_version from standard lsb-release fields
  ...