Log pref file size histogram on read rather than on write.
commitf16b59a08d0a0d8587cd968084a75f6e30799787
authorgab <gab@chromium.org>
Sat, 31 Jan 2015 19:09:02 +0000 (31 11:09 -0800)
committerCommit bot <commit-bot@chromium.org>
Sat, 31 Jan 2015 19:09:53 +0000 (31 19:09 +0000)
tree40fe612a6f86f6b4f7bd5c908501c86b7b97f4cd
parent21d28490ec56bff5d435ed29d776450a0adf4a75
Log pref file size histogram on read rather than on write.

All we care about is the size of the file per user, logging it on write
was wrong as it would generate WAY too many reports as indicated by
issue 453454.

Also changed the distribution to be logarithmic rather than linear to
give better insights (with a linear distribution all we could see was that
most people were below 209KB but we didn't have finer buckets below that).

BUG=453454, 355722

Review URL: https://codereview.chromium.org/891663003

Cr-Commit-Position: refs/heads/master@{#314064}
base/json/json_file_value_serializer.cc
base/json/json_file_value_serializer.h
base/prefs/json_pref_store.cc
tools/metrics/histograms/histograms.xml