GitLab

This CL removes the warning message
  DeprecationWarning: the imp module is deprecated...

from running print_python_deps.py on SuperSize (or other Python 3
projects). The key is to follow the recommendation to use importlib.
Caveats:
* The library only in Python 3, so we need to keep on using imp for
  Python 2.
  * This requires Python version detection and using import statements
    locally.
* importlib.util is more fine-grained than expected, and requires:
  * Manually extracting module name from module path.
  * Explicitly adding loaded module to sys.modules. Meanwhile, once
    the module runs, the modules it transitively uses will be
    automatically added.

Fixed: 1069660
Change-Id: I41b6be8975db1219da006e0c9e5d98b42acf15c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2145094Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758136}