Generate SupportedCSSProperties.js on presubmit

This checks in the SupportedCSSProperties in the source tree file
and ensures that it is kept in sync whenever the third_party
location has been updated.

Bug: 1056614
Change-Id: If0ff2ba0f94f1f0eded2792922e9a917820d9772
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2087762
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
Reviewed-by: Paul Lewis <aerotwist@chromium.org>
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 2dc49c8..d0ad1f2 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -237,6 +237,9 @@
     generated_aria_path = input_api.os_path.join(input_api.PresubmitLocalPath(), 'scripts', 'build', 'generate_aria.py')
     results = _ExecuteSubProcess(input_api, output_api, generated_aria_path, [], results)
 
+    generated_aria_path = input_api.os_path.join(input_api.PresubmitLocalPath(), 'scripts', 'build', 'generate_supported_css.py')
+    results = _ExecuteSubProcess(input_api, output_api, generated_aria_path, [], results)
+
     return results