[Impeller] Remove check_licenses.py (#52970)
I could not find any users of this. As I understand, this was from a time [when Impeller wasn't a part of the
engine](https://github.com/flutter/flutter/issues/97686). Now the engine licenses checkers are sufficient.
diff --git a/ci/licenses_golden/excluded_files b/ci/licenses_golden/excluded_files
index 88babb7..610d517 100644
--- a/ci/licenses_golden/excluded_files
+++ b/ci/licenses_golden/excluded_files
@@ -202,7 +202,6 @@
../../../flutter/impeller/tessellator/tessellator_unittests.cc
../../../flutter/impeller/toolkit/android/README.md
../../../flutter/impeller/toolkit/android/toolkit_android_unittests.cc
-../../../flutter/impeller/tools/check_licenses.py
../../../flutter/impeller/tools/malioc_cores.py
../../../flutter/impeller/tools/malioc_diff.py
../../../flutter/impeller/tools/metal_library.py
diff --git a/impeller/tools/check_licenses.py b/impeller/tools/check_licenses.py
deleted file mode 100644
index 58e6ef0..0000000
--- a/impeller/tools/check_licenses.py
+++ /dev/null
@@ -1,76 +0,0 @@
-# Copyright 2013 The Flutter Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import argparse
-import os
-
-
-def contains_license_block(source_file):
- # This check is somewhat easier than in the engine because all sources need to
- # have the same license.
- py_license = """# Copyright 2013 The Flutter Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file."""
- c_license = py_license.replace('#', '//')
-
- # Make sure we don't read the entire file into memory.
- read_size = (max(len(py_license), len(c_license)))
-
- for lic in [c_license, py_license]:
- with open(source_file) as source:
- if source.read(read_size).startswith(lic):
- return True
-
- return False
-
-
-def is_source_file(path):
- known_extensions = [
- '.cc',
- '.cpp',
- '.c',
- '.h',
- '.hpp',
- '.py',
- '.sh',
- '.gn',
- '.gni',
- '.glsl',
- '.sl.h',
- '.vert',
- '.frag',
- '.tesc',
- '.tese',
- '.yaml',
- '.dart',
- ]
- for extension in known_extensions:
- if os.path.basename(path).endswith(extension):
- return True
- return False
-
-
-# Checks that all source files have the same license preamble.
-def main():
- parser = argparse.ArgumentParser()
- parser.add_argument('--source-root', type=str, required=True, help='The source root.')
- args = parser.parse_args()
-
- assert os.path.exists(args.source_root)
-
- source_files = set()
-
- for root, _, files in os.walk(os.path.abspath(args.source_root)):
- for file in files:
- file_path = os.path.join(root, file)
- if is_source_file(file_path):
- source_files.add(file_path)
-
- for source_file in source_files:
- if not contains_license_block(source_file):
- raise Exception('Could not find valid license block in source ', source_file)
-
-
-if __name__ == '__main__':
- main()
