Eliminate InterfaceDependencies.txt

InterfaceDependencies.txt was used by Perl.
This is no longer necessary in Python, as we pickle
(which is faster and avoids having ad hoc reading/writing).

R=haraken
BUG=341748

Review URL: https://codereview.chromium.org/180273009

git-svn-id: svn://svn.chromium.org/blink/trunk@168264 bbb929c8-8fbe-4397-9dbb-9b2b20218538