File manager concatenates almost all scripts and then compiles it using closure compiler for type checking.
It is tough to maintain the script list.
The relationships between files and restrictions about script order are not clear.
The list needs to be updated when some depended modules (outside file manager) are updated.
In v2 syntax, maintaining script list will be much easier.
However, we need to remove circular dependencies between files to migrate to v2, since we need to declare dependencies explicitly for each files in v2 syntax.
Comment 1 by fukino@chromium.org
, Aug 18 2016