Bug 1559975 - convert layout/style to python3 r=ahal

Differential Revision: https://phabricator.services.mozilla.com/D35699

--HG--
extra : moz-landing-system : lando

layout/style/GenerateCSSPropsGenerated.py

@@ -51,7 +51,7 @@ def generate(output, dataFile):
     # Generate kIDLNameSortPositionTable
     ps = sorted(properties, key=lambda p: p.idlname)
     ps = [(p, position) for position, p in enumerate(ps)]
-    ps.sort(key=lambda (p, position): p.index)
+    ps.sort(key=lambda item: item[0].index)
     output.write("const int32_t nsCSSProps::"
                  "kIDLNameSortPositionTable[eCSSProperty_COUNT] = {\n")
     for (p, position) in ps:

tools/lint/py3.yml

@@ -12,7 +12,7 @@ py3:
         - gfx
         - ipc/ipdl
         - layout/reftests
-        - layout/style
+        - layout/style/ServoCSSPropList.mako.py
         - layout/tools/reftest
         - media
         - security/manager/ssl