Adding PRESUBMIT.py with a bunch of checks turned on

This CL does not retroactively fix violations of the checks, so as new
code is added unrelated failures may appear from older code in the same
file.

Removed the headers= line from CPPLINT.cfg, since it was adding an
extension,.hpp, that we don't use for headers and it is not supported on
all platforms.

BUG=tint:1

Change-Id: I9b2d096cf6c69d1456c857a2fdcd7e7da3fd747b
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/22544
Reviewed-by: David Neto <dneto@google.com>
Reviewed-by: dan sinclair <dsinclair@google.com>

CPPLINT.cfg

@@ -1,2 +1 @@
 set noparent
-headers=h,hpp

PRESUBMIT.py

@@ -0,0 +1,76 @@
+# Copyright 2020 The Tint Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Presubmit script for Tint.
+See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
+for more details about the presubmit API built into depot_tools.
+"""
+
+
+def _LicenseHeader(input_api):
+    """Returns the license header regexp."""
+    # Accept any year number from 2003 to the current year
+    current_year = int(input_api.time.strftime('%Y'))
+    allowed_years = (str(s) for s in reversed(xrange(2019, current_year + 1)))
+    years_re = '(' + '|'.join(allowed_years) + ')'
+    license_header = (
+        r'.*? Copyright( \(c\))? %(year)s The Tint [Aa]uthors\n '
+        r'.*?\n'
+        r'.*? Licensed under the Apache License, Version 2.0 (the "License");\n'
+        r'.*? you may not use this file except in compliance with the License.\n'
+        r'.*? You may obtain a copy of the License at\n'
+        r'.*?\n'
+        r'.*?     http://www.apache.org/licenses/LICENSE-2.0\n'
+        r'.*?\n'
+        r'.*? Unless required by applicable law or agreed to in writing, software\n'
+        r'.*? distributed under the License is distributed on an "AS IS" BASIS,\n'
+        r'.*? WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n'
+        r'.*? See the License for the specific language governing permissions and\n'
+        r'.*? limitations under the License.\n') % {
+            'year': years_re,
+        }
+    return license_header
+
+
+def CheckChange(input_api, output_api):
+    results = []
+
+    results += input_api.canned_checks.CheckChangeHasDescription(
+        input_api, output_api)
+    results += input_api.canned_checks.CheckPatchFormatted(input_api,
+                                                           output_api,
+                                                           check_python=True)
+    results += input_api.canned_checks.CheckGNFormatted(input_api, output_api)
+    results += input_api.canned_checks.CheckChangeHasNoCrAndHasOnlyOneEol(
+        input_api, output_api)
+    results += input_api.canned_checks.CheckChangeHasNoTabs(
+        input_api, output_api)
+    results += input_api.canned_checks.CheckChangeTodoHasOwner(
+        input_api, output_api)
+    results += input_api.canned_checks.CheckChangeHasNoStrayWhitespace(
+        input_api, output_api)
+    results += input_api.canned_checks.CheckDoNotSubmit(input_api, output_api)
+    results += input_api.canned_checks.CheckChangeLintsClean(
+        input_api, output_api)
+    results += input_api.canned_checks.CheckGenderNeutral(
+        input_api, output_api)
+
+    return results
+
+
+def CheckChangeOnUpload(input_api, output_api):
+    return CheckChange(input_api, output_api)
+
+
+def CheckChangeOnCommit(input_api, output_api):
+    return CheckChange(input_api, output_api)