jasongin@ created this patch.
https://github.com/jasongin/nodejs/commit/dcc50445a364664586164f42f9250732bd372982
This patch adds the support to emit a trace event by using a comma-separated
list of categories, so that the trace event will be emitted if there is at least
one category is enabled in the categories list.

TBR=jochen@chromium.org

Review-Url: https://codereview.chromium.org/2558193002
Cr-Commit-Position: refs/heads/master@{#41567}