Fix tracing

Move back to 32 bit method IDs, add a bijective map for method IDs.

Also some cleanup.

(cherry picked from commit d40bcc4fab1589e3aac0f4b59217c6ab4e72102a)

Bug: 19264997
Change-Id: Icdd36591df53ff975d30b9000cfe67d3ae8c51d5
2 files changed