Rename compute_dependencies.py => compute_interfaces_info.py

This CL:
renames compute_dependencies to compute_interfaces_info,
as it does a lot more than just compute dependencies now

Split from:
Split generate_global_constructors.py out of compute_dependencies.py
https://codereview.chromium.org/173803006/

BUG=341748
R=haraken

Review URL: https://codereview.chromium.org/171373006

git-svn-id: svn://svn.chromium.org/blink/trunk@167716 bbb929c8-8fbe-4397-9dbb-9b2b20218538