[tracing] Expose level of detail of memory dumps in the trace JSON

This small CL exposes a "level_of_detail" field in the trace JSON,
as a sibling of "allocators". e.g.,

"dumps":{
 "allocators":{...},
 "allocators_graph":[...],
 "level_of_detail":"light",
 "process_totals":{...}
}

BUG=524345

Review URL: https://codereview.chromium.org/1344543002

Cr-Commit-Position: refs/heads/master@{#348861}


CrOS-Libchrome-Original-Commit: df2ce273eeb2a30602349d3e7f0de5a445abccbc
1 file changed
tree: 965cf76f4ca3f3179387ef9cbb0f98a81fa1d010
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/