Mac packaging: make distributions that can share app bundles do so

Bug: 1142508
Change-Id: I8e310994740653c0d5174528b5b0ef36e9b0e32b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2499881Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822666}

chrome/installer/mac/signing/model.py

@@ -227,6 +227,18 @@ class Distribution(object):
         self.package_as_dmg = package_as_dmg
         self.package_as_pkg = package_as_pkg
 
+    def brandless_copy(self):
+        """Derives and returns a copy of this Distribution object, identical
+        except for not having a branding code.
+
+        This is useful in the case where a non-branded app bundle needs to be
+        created with otherwise the same configuration.
+        """
+        return Distribution(self.channel, None, self.app_name_fragment,
+                            self.packaging_name_fragment, self.product_dirname,
+                            self.creator_code, self.channel_customize,
+                            self.package_as_dmg, self.package_as_pkg)
+
     def to_config(self, base_config):
         """Produces a derived |config.CodeSignConfig| for the Distribution.