Compile time changes from mojo code-gen optimization

Full details can be found in this blog post:

Chromium's IPC system, called "mojo" uses generated .cc files to implement functionality. Some of these files end up containing no actual code, but were still expensive to compile due to their boilerplate #includes. This video animates between the compile times before and after an optimization that removed the #includes from files with no code.
The CL in question can be seen here:

The live visualization can be seen here:

optimization