The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/514d9f3232687f8eb35ffa74993d1b5ad2a0b219

commit 514d9f3232687f8eb35ffa74993d1b5ad2a0b219
Author: Brian White <bcwhite@chromium.org>
Date: Tue Dec 05 19:02:26 2017

Better handling of invalid files in metrics directory.

Previously, when managing a directory of files, only one file was ever
processed per call.  This wasn't a problem because after each call,
another would be scheduled.  However, the "independent" files are
processed by an outside caller and so if the file ready for it turned
out to be invalid, it would see "nothing to be done" and wait an
extended period of time to try again.

The new version does the validity test during the initial check and
immediately advances to the next file if it detects a problem.  This
means there is always a file to process and never a significant delay
before trying the next one.

Bug: 760317,  780036 
Change-Id: I3fece9e41af3b8d29d0fa80b25141c00f9ae9db2
Reviewed-on: https://chromium-review.googlesource.com/804063
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521770}
[modify] https://crrev.com/514d9f3232687f8eb35ffa74993d1b5ad2a0b219/components/metrics/file_metrics_provider.cc
[modify] https://crrev.com/514d9f3232687f8eb35ffa74993d1b5ad2a0b219/components/metrics/file_metrics_provider.h
[modify] https://crrev.com/514d9f3232687f8eb35ffa74993d1b5ad2a0b219/components/metrics/file_metrics_provider_unittest.cc
[modify] https://crrev.com/514d9f3232687f8eb35ffa74993d1b5ad2a0b219/components/metrics/persistent_system_profile.cc
[modify] https://crrev.com/514d9f3232687f8eb35ffa74993d1b5ad2a0b219/components/metrics/persistent_system_profile.h
[modify] https://crrev.com/514d9f3232687f8eb35ffa74993d1b5ad2a0b219/tools/metrics/histograms/enums.xml

Android files are not being uploaded because of the MetricsAndCrashSampling (stable) experiment that sends metrics on only 10% of devices.

Working as intended.