GitLab

This vastly simplifies the backend pipeline needed to symbolize IPC
messages, requiring a simple lookup table rather than symbolization
followed by source code parsing. It also means the raw IPC message
IDs are constant across Chrome versions/builds/platforms, which
facilitates aggregation.

The impact on binary size is roughly a nop; on some platforms slightly
better, on some slightly worse. The overall impact is still about
the same.

BUG=950668

Change-Id: I13661059db79c1b091afdf68daed14325a18f26a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1615386Reviewed-by: François Doray <fdoray@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: oysteine <oysteine@chromium.org>
Commit-Queue: Chris Hamilton <chrisha@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664578}