Bug 1454912 - Revert "Bug 1218999 - Update mtimes when building a GENERATED_FILES target, even when contents don't change."; r=nalexander

We no longer want to update mtimes of FileAvoidWrites so that downstream
rules aren't triggered if the files aren't changed. Since the .stub file
target of GENERATED_FILES are always touched, make won't continually
rebuild them.

MozReview-Commit-ID: GxrFgCJTYk

--HG--
extra : rebase_source : f4412af1dc29142b76f7695627ba3354baf84edd

python/mozbuild/mozbuild/action/file_generate.py

@@ -100,15 +100,6 @@ def main(argv):
                 mk.create_rule([args.dep_target]).add_dependencies(deps)
                 with FileAvoidWrite(args.dep_file) as dep_file:
                     mk.dump(dep_file)
-        # Even when our file's contents haven't changed, we want to update
-        # the file's mtime so make knows this target isn't still older than
-        # whatever prerequisite caused it to be built this time around.
-        try:
-            os.utime(args.output_file, None)
-        except:
-            print('Error processing file "{0}"'.format(args.output_file),
-                  file=sys.stderr)
-            traceback.print_exc()
     except IOError as e:
         print('Error opening file "{0}"'.format(e.filename), file=sys.stderr)
         traceback.print_exc()