As recommended by https://golang.org/pkg/cmd/go/internal/generate/:
To convey to humans and machine tools that code is generated,
generated source should have a line early in the file that
matches the following regular expression (in Go syntax):
^// Code generated .* DO NOT EDIT\.$
A Namespace object is now guaranteed unique.
This cleaned up some old workarounds and latent bugs.
Change-Id: Ic3f12d89947871b03b2c449ba51b3186f953adde
Tested: on Linux.
Bug: 21336857