tree 314b6c23c3fe1ce1475e6b0299809bb410236520
parent 09efa543aeae466a41e59cbb47e3e220a53711b6
author bcwhite <bcwhite@chromium.org> 1499268537 +0900
committer Qijiang Fan <fqj@google.com> 1591306502 +0900

Remove typically unused local_metadata_ field.

The vast majority of histograms and their samples are now "persistent"
with the memory coming from a special memory segment. It's wasteful to
have a "local metadata" structure in each sample object that is never
used.

Instead, allocate the structure from the heap for only those objects
that need it and release it when those objects get destructed.

BUG=733380

Review-Url: https://codereview.chromium.org/2973603002
Cr-Commit-Position: refs/heads/master@{#484282}


CrOS-Libchrome-Original-Commit: b4d87bb384bfc8b43cadc24160c0da01ab09f555