Usage of Chromium‘s gdbinit is recommended when debugging with gdb on any platform. This is necessary for source-level debugging when strip_absolute_paths_from_debug_symbols or use_custom_libcxx are enabled (they’re enabled by default), and also adds extra features like pretty-printing of custom Chromium types.
To use, add the following to your ~/.gdbinit
source /path/to/chromium/src/tools/gdb/gdbinit