This PR migrates `CookieMonster` from macro replacements to be handled
by `plaster`. This is going to be specially useful in `cr149` where a
recent landed changed (https://crrev.com/c/7727488) would force the
introduction of patch files, and become very disruptive for how these
replacement macros work right now in general.
This PR attemps a novel approach to replicate the common pattern where
in Brave we want to replace a Chromium class with a derived Brave class:
the Chromium class is moved into a nested namespace called
`chromium_impl`, and the brave implementation is declared in its place
in a shadow file.
This has required additional plaster for types that absolutely have to
refer to the chromium implementation, but the outcome is much simpler
than the previous invisible replacements.
This change leaves no `#define` uses for replacement in the shadow
files.
Resolve https://github.com/brave/brave-browser/issues/54496
cdesouza-chromium
aa5bd05238