tracing: Allow empty call to OnTraceData

This change makes it legal for a TracingBackend to call OnTraceData with
zero bytes to signal the end of trace data. This makes it easier to
implement a trace consumer backend in scenarios where trace data and
the EOF signal are delivered separately, i.e., when the backend knows
there's no more data to come, it has already sent all the data to the
consumer.

Bug: 158460267

Change-Id: Ibb918845a0d64d7890a954ad8308d4e8c84e712a
1 file changed
tree: d931b597aa854c38198e7badd68b6907c8d72b4b
  1. bazel/
  2. build_overrides/
  3. buildtools/
  4. debian/
  5. docs/
  6. examples/
  7. gn/
  8. include/
  9. infra/
  10. protos/
  11. src/
  12. test/
  13. tools/
  14. ui/
  15. .clang-format
  16. .gitignore
  17. .gn
  18. .style.yapf
  19. Android.bp
  20. Android.bp.extras
  21. BUILD
  22. BUILD.extras
  23. BUILD.gn
  24. codereview.settings
  25. heapprofd.rc
  26. LICENSE
  27. METADATA
  28. MODULE_LICENSE_APACHE2
  29. OWNERS
  30. perfetto.rc
  31. PRESUBMIT.py
  32. README.chromium
  33. README.md
  34. TEST_MAPPING
  35. traced_perf.rc
  36. WORKSPACE
README.md

Perfetto - System profiling, app tracing and trace analysis

Perfetto is a production-grade open-source stack for performance instrumentation and trace analysis. It offers services and libraries and for recording system-level and app-level traces, native + java heap profiling, a library for analyzing traces using SQL and a web-based UI to visualize and explore multi-GB traces.

See https://docs.perfetto.dev or the /docs/ directory for documentation.