Add .clang-format files and format more files

The .clang-format files tell clang-format to ignore certain directories
(replacing code in lint_clang_format.sh which will be removed).

$ git ls-tree -r master --name-only | grep '\.\(c\|h\|cpp\|gn\|gni\|mm\|m\|py\)$' | xargs ./append-space-to-files
$ git checkout -- generator/templates third_party/khronos/{KHR,vulkan}
$ git cl format --full --python

Followed by manual reformatting of a few things in Python for
readability.

Bug: none
Change-Id: I4c9e472cc9a5cd80c07286e808f4e597cfef5428
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/24785
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>

PRESUBMIT.py

@@ -16,6 +16,7 @@ import os
 import platform
 import subprocess
 
+
 def _DoClangFormat(input_api, output_api):
     if platform.system() == 'Linux' and platform.architecture()[0] == '64bit':
         clang_format_path = 'buildtools/linux64/clang-format'
@@ -32,9 +33,7 @@ def _DoClangFormat(input_api, output_api):
         return []
 
     lint_cmd = [
-        'scripts/lint_clang_format.sh',
-        clang_format_path,
-        upstream_commit
+        'scripts/lint_clang_format.sh', clang_format_path, upstream_commit
     ]
 
     # Call the linting script and forward the output as a notification or as an error
@@ -44,15 +43,20 @@ def _DoClangFormat(input_api, output_api):
     except subprocess.CalledProcessError as e:
         return [output_api.PresubmitError(e.output)]
 
+
 def _DoCommonChecks(input_api, output_api):
     results = []
-    results.extend(input_api.canned_checks.CheckChangedLUCIConfigs(input_api, output_api))
-    results.extend(input_api.canned_checks.CheckGNFormatted(input_api, output_api))
+    results.extend(
+        input_api.canned_checks.CheckChangedLUCIConfigs(input_api, output_api))
+    results.extend(
+        input_api.canned_checks.CheckGNFormatted(input_api, output_api))
     results.extend(_DoClangFormat(input_api, output_api))
     return results
 
+
 def CheckChangeOnUpload(input_api, output_api):
     return _DoCommonChecks(input_api, output_api)
 
+
 def CheckChangeOnCommit(input_api, output_api):
     return _DoCommonChecks(input_api, output_api)