Change shabang to run vpython3 for coverage.py.

As seen in https://crrev.com/922986, tools/code_coverage/coverage.py can
be used with vpython3, so use that in the shabang and let it run with
Python 3 by default.

Fix a presubmit error for lines over 80 columns along the way.

Change-Id: I83e4bfbdd14a97953d0dddfea111a9f7e1e800ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3504504
Reviewed-by: Yuke Liao <[email protected]>
Commit-Queue: Lei Zhang <[email protected]>
Cr-Commit-Position: refs/heads/main@{#978376}
diff --git a/tools/code_coverage/coverage.py b/tools/code_coverage/coverage.py
index 8c0c24e..ec6b3b7 100755
--- a/tools/code_coverage/coverage.py
+++ b/tools/code_coverage/coverage.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env vpython
+#!/usr/bin/env vpython3
 # Copyright 2017 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -252,8 +252,8 @@
   logging.debug('Finished running "llvm-cov show" command.')
 
 
-def _GeneratePerFileLineByLineCoverageInLcov(binary_paths, profdata_file_path, filters,
-                                             ignore_filename_regex):
+def _GeneratePerFileLineByLineCoverageInLcov(binary_paths, profdata_file_path,
+                                             filters, ignore_filename_regex):
   """Generates per file line-by-line coverage using "llvm-cov export".
 
   Args: