Enable presubmit check for copyrighted material in added / modified code

PRESUBMIT.py

 # Copyright (c) 2012 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.
 
 """Top-level presubmit script for Chromium.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into gcl.
 """
 
@@ skipping 1244 matching lines @@
         input_api.PresubmitLocalPath(), 'tools', 'android', 'checkstyle')]
     import checkstyle
   finally:
     # Restore sys.path to what it was before.
     sys.path = original_sys_path
 
   return checkstyle.RunCheckstyle(
       input_api, output_api, 'tools/android/checkstyle/chromium-style-5.0.xml')
 
 
+def _CheckForCopyrightedCode(input_api, output_api):
+  """Verifies that newly added code doesn't contain copyrighted material
+  and is properly licensed under the standard Chromium license.
+
+  As there can be false positives, we maintain a whitelist file. This check
+  also verifies that the whitelist file is up to date.
+  """
+  import sys
+  original_sys_path = sys.path
+  try:
+    sys.path = sys.path + [input_api.os_path.join(
+        input_api.PresubmitLocalPath(), 'android_webview', 'tools')]
+    import copyright_scanner
+  finally:
+    # Restore sys.path to what it was before.
+    sys.path = original_sys_path
+
+  return copyright_scanner.ScanAtPresubmit(input_api, output_api)
+
+
 _DEPRECATED_CSS = [
   # Values
   ( "-webkit-box", "flex" ),
   ( "-webkit-inline-box", "inline-flex" ),
   ( "-webkit-flex", "flex" ),
   ( "-webkit-inline-flex", "inline-flex" ),
   ( "-webkit-min-content", "min-content" ),
   ( "-webkit-max-content", "max-content" ),
 
   # Properties
@@ skipping 95 matching lines @@
           output_api,
           source_file_filter=lambda x: x.LocalPath().endswith('.grd')))
   results.extend(_CheckSpamLogging(input_api, output_api))
   results.extend(_CheckForAnonymousVariables(input_api, output_api))
   results.extend(_CheckCygwinShell(input_api, output_api))
   results.extend(_CheckUserActionUpdate(input_api, output_api))
   results.extend(_CheckNoDeprecatedCSS(input_api, output_api))
   results.extend(_CheckNoDeprecatedJS(input_api, output_api))
   results.extend(_CheckParseErrors(input_api, output_api))
   results.extend(_CheckForIPCRules(input_api, output_api))
+  results.extend(_CheckForCopyrightedCode(input_api, output_api))
 
   if any('PRESUBMIT.py' == f.LocalPath() for f in input_api.AffectedFiles()):
     results.extend(input_api.canned_checks.RunUnitTestsInDirectory(
         input_api, output_api,
         input_api.PresubmitLocalPath(),
         whitelist=[r'^PRESUBMIT_test\.py$']))
   return results
 
 
 def _CheckAuthorizedAuthor(input_api, output_api):
@@ skipping 397 matching lines @@
   ]
 
   # Match things like path/aura/file.cc and path/file_aura.cc.
   # Same for chromeos.
   if any(re.search(r'[\\\/_](aura|chromeos)', f) for f in files):
     builders.extend([
         'linux_chromeos_asan',
     ])
 
   return GetDefaultTryConfigs(builders)