tracing: restructure to the components/tracing folder

This is a non functional refactoring. This is just reshuffling files
inside //components/tracing in preparation for bitt.ly/TracingV2,
which will introduce new files.

BUG=608719
[email protected],[email protected],[email protected],[email protected]

Review-Url: https://codereview.chromium.org/2028043002
Cr-Commit-Position: refs/heads/master@{#397260}
52 files changed