FileImpl interface is removed by this patch in 'gclient' tool: https://codereview.chromium.org/2398493004. See the code snippet in this revision at https://codereview.chromium.org/2398493004/diff/60001/gclient.py. 

After remove the corresponding code in roll_webgl_conformance.py and roll_angle.py, these two tools work again. See the patch at https://codereview.chromium.org/2435723003/. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/aed818075281e5bf3a2f8984f170102cff5e7469

commit aed818075281e5bf3a2f8984f170102cff5e7469
Author: yunchao.he <yunchao.he@intel.com>
Date: Sat Oct 22 01:03:56 2016

Fix bug for the webgl and angle roll-in tools

BUG= 657723 

Review-Url: https://chromiumcodereview.appspot.com/2435723003
Cr-Commit-Position: refs/heads/master@{#426939}

[modify] https://crrev.com/aed818075281e5bf3a2f8984f170102cff5e7469/tools/roll_angle.py
[modify] https://crrev.com/aed818075281e5bf3a2f8984f170102cff5e7469/tools/roll_webgl_conformance.py

I think the bug is fixed now.