Optimize memory use of registered histograms.
Prior to this change, all histogram names would be stored
twice - once in each Histogram object and another time as
the key of the histograms map. This change eliminates the
second copy by making the map key be a reference to the
name string within the Histogram object.
In my local testing, this saved about 35k of memory in the
browser process and around 2k-4k in each sub-process.
BUG=500619
Review URL: https://codereview.chromium.org/1181293005
Cr-Commit-Position: refs/heads/master@{#334481}
CrOS-Libchrome-Original-Commit: 33d9fd6321af0d2905adb9f5168d853e3b45248c
3 files changed