Originally, the annotation layer initialization happens inside the
attached callback of the gr-diff-builder, and one problem with this
design is that in the diff view page, the attached() is usually called
before the plugins are installed, which means that the extra plugin
specific layers won't be picked up.
Moving the logic to render() would partially fix the issue because following
events usually happen in orders:
[diff-builder attached] -> [plugin installs] -> [diff-builder render].
However, above order is not garanteened because plugins are loaded one
by one, and they don't block diff loading and rendering. There may be a
case when plugin is loaded after diff rendering is started, so a better
solution needs to be implemented later.
Bug: Issue 10054
Change-Id: I944ee7ee5bdf68ee523f2428d692fb94bd5a7c47
2c9eb2d7cf